nwmtg 


Name  of  Book  and  Volume, 


Division .... 


Range 

Shelf.. 

eceived....  ..187 


University  of  California, 

THE  MEDICAL.  LIBRARY 


y.    .1  .     For  110  EATJIX    M.   D. 

Of  San  Francisco. 

PRESENTED  BY  MBS,  AND  MISS  FOTJEGEATJD. 
i  I:UKI   i  I:Y.  /«;.>. 


WORKS  ON  CHEMICAL  SCIENCE, 

PUBLISH  KD  P»Y  BLANCIIAKD   AND   LKA. 

A  MANUAL  OF  ELEMENTARY  CHEMISTRY;  THEORETICAL  AND 
PRACTICAL.  By  GEORGE  FOWNBS,  Ph.  D.  Ac.  From  the  seventh  re- 
\  IMM!  and  corrected  London  edition.  With  one  hundred  and  ninety-seven 
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ELEMENTS  OF  INORGANIC  CHEMISTRY,  including  the  Applications 
of  the  Science  in  the  Arts.  By  THOMAS  GRAHAM,  F.  R.  S.,  late  Professor 
of  Chemistry  in  University  College,  London.  New  and  much  enlarged 
edition,  by  HENRY  WATTS  and  ROBERT  BRIDGES.  Complete  in  one  large 
and  handsome  octavo  volume,  of  over  800  pages,  with  232  wood-cuts; 
price,  in  extra  cloth,  $4.00;  in  leather,  $4.50. 

HANDBOOK  OF  CHEMISTRY;  THEORETICAL,  PRACTICAL,  AND 
TECHNICAL.  By  F.  A.  ABEL,  F.  C.  S.,  and  C.  L.  BLOXAM.  With  a 
Recommendatory  Preface  by  A.  W.  HOFFMAN,  Ph.  D.  With  illustrations. 
In  one  large  octavo  volume  of  662  pages.  Price,  extra  cloth,  $3.25. 

INTRODUCTION  TO  PRACTICAL  CHEMISTRY,  INCLUDING  ANALY- 
SIS. By  JOHN  E.  BOWMAN,  M.  D.  With  numerous  illustrations.  Second 
American,  from  the  Second  and  Revised  English  edition.  In  one  neat 

"    rnva.1  12ino.  volume  of  350  pages.     Price,  extra  cloth,  $1.25. 

ICAL  CHEMISTRY.     By  C.  G.  LEHMA'NN.     Translated  from 

edition  by  GEORGE  E.  DAY,  M.  D.,  F.  R.  S.,  <fcc.     Edited  by 

KRS,  M.  D.,  Professor  of  Chemistry  in  the  Medical  Department 

liversity   of  Pennsylvania.      With    illustrations   selected   from 

tlas  of  Physiological  Chemistry,  and  an  Appendix  of  Plates, 
in  two  large  and  handsome  octavo  volumes,  containing  1200 
about  200  illustrations.  Extra  cloth,  $6. 

F  CHEMICAL  PHYSIOLOGY.     By  C.  G.  LEHMANN.     Trans- 
the  German  by  J.  CHESTON  MORRIS,  M.  D.     With  an  Intro- 
say  on  Vital  Force,  by  Prof.  SAMUEL  JACKSON,  M.  D.,  of  tho 
of  Pennsylvania.     With  illustrations  on  wood.     In  one  hand- 
some >•,      ro  volume  of  336  pages.     Price,  extra  cloth,  $2.25. 

CrY ;  OR  CHEMISTRY  APPLIED  TO  THE  ARTS  AND  TO 
CTURES.  By  Professor  F.  KNAPP.  Edited,  with  numerous 
additions,  by  Dr.  EDMUND  RONALDS  and  Dr.  THOMAS  RICHARD- 
h  American  additions  by  Prof.  WALTER  R.  JOHNSON.  In  two 
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,  PHARMACY:  THE  ARRANGEMENTS,  APPARATUS, 
XIPULATIONS  OF  THE  PHARMACEUTICAL  SHOP  AND 
CORY.  By  FRANCIS  MOHR,  Ph.  D.,  and  THEOPHILUS  REDWOOD, 
)f  Chemistry  and  Pharmacy  to  the  Pharmaceutical  Society  of 
ain.  Edited,  with  extensive  additions,  by  WILLIAM  PROCTER, 
>sor  of  Pharmacy  in  the  Philadelphia  College  of  Pharmacy, 
illustrations.  In  one  very  handsome  octavo  volume  of  nearly 
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DUCTION  TO  PRACTICAL   PHARMACY:    DESIGNED  AS  A 
K  FOR  THE  STUDENT  AND  AS  A  GUIDE  FOR  THE  PHYSICIAN  AND 
KUTIST.    WITH  MANY  FORMULA  AND  PRESCRIPTIONS.     ByEu- 
»  ; .IRISH,  Principal  of  the  School  of  Practical  Pharmacy,  Philadel- 
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trations.    In   one  large  and  handsome   octavo  volume.      (Preparing  for 
early  Publication.) 


CHEMISTRY. 

BY  WILLIAM  T.  BRANDE,  D.  C.  L., 

Of  Her  Majesty's  Mint, 


ALFRED  S.  TAYLOR,  M.  D.,  F.  R.  S., 

Professor  of  Chemistry  and  Medical  Jurisprudence  in  Guy's  Hospital. 

In  one  handsome  octavo  volume  of  about  700  pages.    Price,  in  extra  cloth, 

$3.50. 

"  Having  been  engaged  in  teaching  Chemistry  in  this  Metropolis  the  one 
for  a  period  of  forty,  and  the  other  for  a  period  of  thirty  years,  it  has  appeared 
to  us  that,  in  spite  of  the  number  of  books  already  existing,  there  was  room 
for  an  additional  volume,  which  should  be  especially  adapted  for  the  use  of 
students.  In  preparing  such  a  volume  for  the  press,  we  have  endeavored  to 
bear  in  mind,  that  the  student  in  the  present  day  has  much  to  learn,  and  but 
a  short  time  at  his  disposal  for  the  acquisition  of  this  learning." — AUTHOR'S 
PREFACE. 

In  reprinting  this  volume,  its  passage  through  the  press  has  been  superin- 
tended by  a  competent  chemist,  who  has  sedulously  endeavored  to  secure 
the  accuracy  so  necessary  in  a  work  of  this  nature.  No  notes  or  additions 
have  been  introduced,  but  the  publishers  have  been  favored  by  the  authors 
with  some  corrections  and  revisions  of  the  first  twenty-one  chapters,  which 
have  been  duly  inserted. 

It  needs  no  great  sagacity  to  foretell  that  this  book  will  be,  literally,  the  Handbook 
in  Chemistry  of  the  student  and  practitioner.  For  clearness  of  language,  accuracy  of 
description,  extent  of  information,  and  freedom  from  pedantry  and  mysticism  of 
modern  chemistry,  no  other  text-book  comes  into  competition  with  it.  The  result  is 
a  work  which  for  fulness  of  matter,  for  lucidity  of  arrangement,  for  clearness  of 
style,  is  as  yet  without  a  rival.  And  long  will  it  be  without  a  rival.  For,  although 
with  the  necessary  advance  of  chemical  knowledge  addenda  will  be  required,  there 
will  be  little  to  take  away.  The  fundamental  excellences  of  the  book  will  remain, 
preserving  it  for  years  to  come,  what  it  now  is,  the  best  guide  to  the  study  of  Chemis- 
try yet  given  to  the  world.—  London  Lancet,  Dec.  20,  1862. 

Most  assuredly,  time  has  not  abated  one  whit  of  the  fluency,  the  vigor,  and  the 
clearness  with  which  they  not  only  have  composed  the  work  before  us,  but  have,  so 
to  say,  cleared  the  ground  for  it,  by  hitting  right  and  left  at  the  affectation,  mysti- 
cism, and  obscurity  which  pervade  some  late  chemical  treatises.  Thus  conceived, 
and  worked  out  in  the  most  sturdy,  common  sense  method,  this  book  gives,  in  the 
clearest  and  most  summary  method  possible,  all  the  facts  and  doctrines  of  chemistry, 
with  more  especial  reference  to  the  wants  of  the  medical  student. — London  Medical 
Times  and  Gazette,  Nov.  29,  1862. 

If  we  are  not  very  much  mistaken,  this  book  wilt  occupy  a  place  which  none  has 
hitherto  held  among  chemists ;  for,  by  avoiding  the  errors  of  previous  authors,  we 
have  a  work  which,  for  its  size,  is  certainly  the  most  perfect  of  any  in  the  English 
language.  There  are  several  points  to  be  noted  in  this  volume  which  separate  it 
widely  from  any  of  its  compeers — its  wide  application,  not  to  the  medical  student 
only,  nor  to  the  student  in  chemistry  merely,  but  to  every  branch  of  science,  art,  or 
commerce  which  is  in  any  way  connected  with  the  domain  of  chemistry. — L<rn<l»n 
Med.  Review,  Feb.  1863. 

This  book  has  been  written  for  the  express  purposes  of  the  student  of  chemistry  by 
two  masters  of  the  science.  If  ever  two  writers  could  claim  to  know  what  the  stu- 
dent requires  in  the  way  of  a  handbook  to  help  him  to  a  knowledge  of  the  science, 
Drs.  Brande  and  Taylor  are  the  men.  To  criticize  such  a  manual  as  this  seems,  there- 
fore, a  superfluity.— British  Med.  Journal,  Jan.  21, 1863. 

An  elementary  treatise  from  two  of  our  most  veteran  teachers  and  gi-eatest  authori- 
ties on  chemistry,  compels  a  welcome  reception.  There  is  a  novelty  in  this  book  of 
Drs.  Brande  and  Taylor  which  will  doubtless  secure  for  it  a  principal  place  among 
text-books  for  chemical  students.  Of  the  execution  of  this  work  as  conceived  by  the 
authors  it  is  idle  to  speak.  Their  names  aloue  are  a  sufficient  guarantee  for  its  com- 
.—  The.  M<>.<n<'«l  Ontic,  Jan.  1S63. 

Blanchaid  &  Lea,  Philadelphia. 


PRACTICAL    HANDBOOK 


MEDICAL  CHEMISTRY 


BY 

JOHN  E.  BOWMAN,  F.C.S., 

FORMERLY  PROFESSOR  OF  PRACTICAL  CHEMISTRY  IN  KING'S  COLLEGE,  LONDON. 
EDITED    KY 

CHARLES  L.  BLOXAM, 

PROFESSOR  OF  PRACTICAL  CHEMISTRY  IN  KING'S  COLLEGE,  LONDON*. 


THIRD  AMERICAN 

FROM  THE  FOURTH  AND  REVISED  LONDON  EDITION 

WITH   ILLUSTRATIONS. 


PHILADELPHIA : 

BLANCHAKD    AND    LEA. 
1863. 


PHILADELnilA  : 
COLLINS,  PRINTER,   705  JAYNK   STREET. 


PREFACE 
TO  THE  FOURTH  EDITION. 


DURING  the  seven  years  which  have  elapsed  since 
the  publication  of  the  third  edition  of  this  work, 
considerable  advances  have  been  made  in  the  prac- 
tical part  of  Medical  Chemistry. 

The  Editor  has  endeavored  to  represent  these 
as  fully  as  is  consistent  with  the  concise  and  simple 
character  which  constitutes  one  of  the  great  merits 
of  Bowman's  "  Handbook,"  always  remembering 
that  the  processes  described  should  be  such  as  can 
be  carried  out  by  the  medical  student,  with  the 
resources  of  the  medical  school  and  the  hospital. 

In  the  chapters  on  the  Analysis  of  Urine,  where 
the  greatest  services  are  rendered  by  chemistry  to 
clinical  medicine,  processes  have  been  introduced 
for  the  quantitative  determination  of  krcatinine 
and  of  ammonia,  and  the  methods  of  determining 
them  have  been  carefully  revised  at  the  laboratory 


Vi  PREFACE. 

table.  The  application  of  the  volumetric  principle 
to  the  analysis  of  urine  has  been  extended  as  far 
as  it  appears  to  be  safe,  since  the  rapidity  with 
which  volumetric  determinations  may  be  executed, 
with  great  relative  accuracy,  and  without  demand- 
ing great  skill  on  the  part  of  the  analyst,  recom- 
mends this  method  strongly  to  the  attention  of  the 
medical  practitioner. 

Short  practical  directions  for  the  examination  of 
the  solid  excrements,  of  bile,  and  of  the  liquids  of 
muscular  flesh  have  been  added ;  but  chyle,  lymph, 
&c.  have  been  omitted,  as  not  generally  obtainable 
for  analysis. 

Much  improvement  remains  to  be  made  in  the 
difficult  examination  of  mixed  fluids  for  the  proxi- 
mate constituents  of  animal  bodies,  though  the 
recent  researches  of  English  and  Continental  che-( 
mists  have  enabled  the  editor  to  make  some  addi- 
tions, which,  it  is  hoped,  will  prove  useful. 

Since  the  examination  for  poisons  in  organic 
mixtures  is  comparatively  seldom  undertaken, 
except  by  the  professional  chemist,  the  additions 
which  have  been  made  to  that  part  of  the  work 
presuppose  considerable  familiarity  with  chemical 
manipulations ;  though  it  has  not  been  forgotten 
that,  for  the  purposes  of  a  judicial  inquiry,  the 


PREFACE.  Vll 


medical  man  often  requires  a  knowledge  of  the 
best  processes  for  the  detection  of  poison,  though 
not  desiring  to  carry  them  out  himself. 

Believing  that  the  revival  of  the  electrolytic 
method  for  the  detection  of  metallic  poisons  will 
give  greater  confidence  in  chemico-legal  investiga- 
tions, the  editor  has  fully  described  its  application. 

Short  chapters  have  been  added  upon  the  detec- 
tion of  strychnia,  nicotia,  phosphorus,  and  alcohol, 
in  organic  mixtures. 

The  general  systematic  course  for  the  detection 
of  poisons  in  organic  mixtures  has  been  tested  by 
mixing  minute  quantities  of  the  poisonous  sub- 
stances to  which  it  refers  with  articles  of  food,  and 
proving  that  the  directions  given  would  certainly 
lead  to  their  detection. 

The  concluding  chapter  contains  some  concise 
directions  for  the  application  of  the  elegant  pro- 
cess of  dialysis,  introduced  by  Professor  Graham, 
to  the  separation  of  poisons  from  organic  mixtures. 


KING'S  COLLEGE,  LONDON, 
October,  1862. 


PREFACE 
TO  THE  THIRD  EDITION. 


THE  rapid  sale  of  two  large  editions  of  this  little 
work  encourages  me  to  hope  that  I  was  not  alto- 
gether unsuccessful  in  supplying  a  deficiency  in 
medical  literature  which  has  been  long  felt  by  a 
large  body  of  the  Profession,  as  well  as  in  furnish- 
ing a  plain  and  trustworthy  text-book  for  the 
Medical  Student. 

In  the  present  edition  I  have  endeavored,  with- 
out materially  adding  to  it,  to  embody  all  the 
recent  discoveries  in  Medical  Chemistry  which  have 
been  announced  up  to  the  present  time,  and  thus 
to  keep  pace  with  the  rapid  advance  which  is  every 
year  being  made  in  this  most  important  branch  of 
medical  science. 


JOHN  E.  BOWMAN. 


KING'S  COLLEGE,  LONDON, 
January,  1855. 


PREFACE 

TO  THE  FIRST  EDITION. 


THE  want  which,  as  a  teacher  of  Practical  Che- 
mistry in  a  Medical  School,  I  have  long  felt,  of  a 
small  manual  containing  instructions  for  the  exa- 
mination and  analysis  of  urine,  blood,  and  a  few 
other  of  the  more  important  animal  products,  both 
healthy  and  morbid,  and  comprising  also  directions 
for  the  detection  of  poisons  in  organic  mixtures 
and  in  the  tissues,  was  my  chief  inducement  in 
undertaking  to  write  the  present  little  work. 

In  doing  this,  my  endeavor  has  been  to  supply  a 
book  that  will  be  found  useful,  not  only  to  the 
Medical  Student,  but  also  to  the  Practitipncr,  to 
whom  the  value  and  importance  of  the  applications 
of  modern  chemistry  and  microscopic  analysis  to 
his  art  arc  becoming  daily  more  and  more  apparent. 

The  writers  to  whom  I  have  been  chiefly  indebted 
are  Drs.  Golding  Bird,  Owen  llees,  Day,  Franz 


Xll  PREFACE. 

Simon,  Vogel,  and  Donne.  My  warm  acknowledg- 
ments are  also  due  to  my  friend  and  colleague, 
Professor  Miller,  who,  in  addition  to  much  other 
valuable  assistance,  kindly  undertook  to  revise  the 
proof-sheets  during  their  passage  through  the 
press. 

J.  E.  BOWMAN. 

KING'S  COLLEGE,  LONDON, 
April,  1850. 


CONTENTS. 


PART   I.— URINE. 

CHAPTER   I. 

PACK 

HEALTHY  URINE  ......  25 

The  extraction,  composition,  and  properties  of  the  several 
constituents  of  healthy  urine;  Urea,  Uric  Acid,  Hippuric 
Acid,  Kreatinine,  Mucus,  Extractive  and  Coloring  Matters, 
Ammoniacal  Salts,  Fixed  Alkaline  Salts,  and  Earthy  Salts. 
Quantitative  Determination  of  Kreatinine. 
Separation  of  Indigo-blue  from  Healthy  Urine. 

CHAPTER  II. 

QUANTITATIVE  ANALYSIS  OF  HEALTHY  URINE    ...  48 

Determination  of  Water,  Urea,  Uric  Acid,  and  Salts. 
Determination  of  Ammonia. 
Quantitative  Analysis  of  the  Ash  of  Urine. 
Determination  of  Alkaline  and  Earthy  Phosphates,  Sulphuric 

Acid,  and  Chlorine  in  the  Original  Urine. 
Volumetric  determination  of  Phosphates  in  Urine. 
Determination  of  the  degree  of  Acidity. 

CHAPTER  III. 

AVERAGE  COMPOSITION  OF  HEALTHY  URINE       ...  61 

Results  obtained  by  Berzelius,  Simon,  Miller,  Marchand,  Leh- 
inanu,  and  Becquerel. 

CHAPTER  IV. 

MORBID  URINE   .......  63 

Detection  of  Abnormal  proportions  of  Urea,  Uric  Acid,  Urate 
of  Ammonia,  Urate  of  Soda,  Hippuric  Acid,  Mucus,  Coloring 
Matters,  and  Salts. 

Urine  containing  Sugar.  Tests  for  Sugar  proposed  by  Trom- 
raer,  Maumene,  Moore,  Buttger,  and  Briicke.  Fermentation 
Test. 

Detection  of  Sugar  in  Healthy  Urine. 
9 


XIV  CONTENTS. 


PAGE 

New  substance,  Alkapton,  simulating  Sugar  in  Urine. 

Albuminous  Urine.     Detection  of  Blood  in  Urine. 

Urine  containing  Biliary  Matter.  Pettenkofer's,  Heller's,  and 
Gmelin's  Tests  for  Bile. 

Presence  of  Pus,  Fatty  and  Chylous  Matter,  Kiestein,  and  Se- 
men in  Urine. 

Detection  of  Oxalate  of  Lime,  Cystine,  &c.,  in  Urine. 


CHAPTER  V. 

EXAMINATION  OF  URINE  SUSPECTED  TO  CONTAIN  EITHER  AN  UNNATURAL 
PROPORTION  OF  SOME  ONE  OR  MORE  OF  THE  USUAL  INGREDIENTS,  OR 
ELSE  SOME  ABNORMAL  MATTER  ....  94 

Quantitative  Estimation  of  Urea  by  Liebig's  process. 
Methods  of  determining  Urea  proposed  by  Leconte  and  E. 
Davy. 

CHAPTER  VI. 

EXAMINATION  OF  MORBID  URINE,  THE   NATURE  OF  WHICH  is  ALTO- 
GETHER UNKNOWN       ......  122 

Identification  of  Urinary  Deposits. 
Systematic  Examination  of  the  Clear  Urine. 
Microscopic  Examination  of  Urinary  Deposits. 

CHAPTER  VII. 

QUANTITATIVE  ANALYSIS  OF  DIABETIC  URINE      .  .  .  137 

Volumetric  Determination  of  Sugar  by  an  Alkaline  Solution 

of  Tartrate  of  Copper. 
Analyses  of  Diabetic  Urine  by  Simon,  Percy,  and  Bouchardat. 


CHAPTER  VIII. 

QUANTITATIVE  ANALYSIS  OF  ALBUMINOUS  URINE  .  .  146 

Analyses  of  Albuminous  Urine  by  Simon  and  Percy. 


PART  II.— CALCULI  AND  CONCRETIONS. 


CHAPTER  I. 

URINARY  CALCULI        ......  150 

Identification  of  Calculi  composed  of  Uric  Acid,  Xanthine, 
Urate  of  Ammonia,  Phosphate  of  Lime,  Triple  Phosphate, 
Oxalate  of  Lime,  Urate  of  Lime,  or  Cystine. 


CONTENTS.  XV 

CHAPTER  II. 

PAGE 

SYSTEMATIC  COURSE  FOR  THE  EXAMINATION  OF  CALCULI,  THE  COMPO- 
SITION OF  WHICH  IS  UNKNOWN  ....  159 

CHAPTER  III. 

BILIARY  CALCULI  OR  GALL-STONES          ...  163 

Composition  and  properties  of  Cholesterin. 
Thudichuin's  process  for  the  Analysis  of  Biliary  Calculi. 

CHAPTER  IV. 

GOUTY  CONCRETIONS       .  .  .  .  .  .          1G4 

Qualitative  Analysis  of  Gouty  Concretions. 

CHAPTER  V. 

SOLID  EXCREMENTS         .  .  .  .  .  .^167 

Marcet's  process  for  Separating  the  Proximate  Principles  con- 
tained in  the  Feces. 
Excretiue  and  Excretolic  Acid. 


PART  III.— BLOOD. 

CHAPTER  I. 
HEALTHY  BLOOD  .  .  .  .  .  .169 

General  Characters  of  Blood. 

Separation  of  its  Proximate  Constituents ;  Blood  Corpuscles, 

Albumen,  Fibrine,  Extractive,  Fatty,  and  Saline  Matters. 
Recognition  of  Blood-stains  on  Textile  Fabrics,  and  on  Iron. 
Extraction  and  Properties  of  Hsenuitin. 
Haematoidin.     Blood  crystals. 

CHAPTER  II. 

QUANTITATIVE  ANALYSIS  OF  BLOOD  ....         190 

Analysis  of  Coagulated  and  Uncoagulated  Blood. 
Average  Composition  of  Healthy  Blood. 

Results  obtained  by  Dumas,  Simon,  Becquerel  and  Rodier, 
Lehmann  and  Enderlin. 

CHAPTER  III. 

MORBID  BLOOD  .  .  .  .  .  .  .210 

Detection  of  Abnormal  Proportions  of  Water,  Corpuscles,  Al- 
bumen, Fibrine,  Fatty  Matter,  Cholesterin,  Urea,  and  Salts. 
Blood  containing  Sugar,  Biliary  Matter,  Pus,  and  Animalcules. 


XVI  CONTENTS. 

PART  IV.— MILK,  BILE,  MUCUS,  PUS,  &o. 

CHAPTER  I. 

PAGE 

MILK      .  .  .  .  .  .  .  .224 

General  Characters  of  Milk. 

Extraction  and  Identification  of  the  Caseine,  Lactine,  Fat  and 

Saline  Matters  in  Milk. 
Composition  of  Human  Milk,  according  to  Simon,  Clemm, 

Chevallier  and  Henri,  Vernois  and  Becquerel. 
Composition  of  the  Milk  of  other  Animals. 
Results  obtained  by  Chevallier  and  Henri,  and  by  Morin. 
Galactine. 

CHAPTER  II. 

QUANTITATIVE  ANALYSIS  OF  MILK  ....          232 

Volumetric  Determination  of  Lactine. 

CHAPTER  III. 

MILK  DURING  DISEASE    ......  234 

Composition  of  the  Colostrum. 

CHAPTER  IV. 

THE  ADULTERATIONS  OP  MILK     .  .  .  .  .236 

Detection  of  Starch,  Gum,  Annato,  £c. 
Use  of  the  Lactometer. 
DaubrawVs  process  for  the  Valuation  of  Milk. 

CHAP1LER  V. 

BILE      ........          239 

Composition  of  Bile. 

Extraction  and  Properties  of  Cholic  and  Choleic  Acids. 

Taurine.     Biliverdine.     Biliphaeine. 

Sugar-forming  Substance  in  the  Liver. 

CHAPTER  VI. 

JUICE  OP  FLESH  .......          242 

Preparation  and  Properties  of  Kreatine. 
Kreatinine.     Sarcine.     Inosite. 

Extraction  of  Sarco-lactic  and  Butyric  Acids  from  Juice  of 
Flesh. 


CONTENTS.  XVII 

CHAPTKR  VII. 

PAGE 

Mucus  ........          245 

Quantitative  Estimation  of  its  Proximate  Constituents. 
Morbid  Conditions  of  Mucus. 

CHAPTER  VIII. 

Pus        ........          249 

General  Characters  and  Quantitative  Analysis  of  Pus. 
Blue  Pus.     Pyocyanine. 

CHAPTER  IX. 

BONE 254 

Quantitative  Analysis  of  Bone. 

Chancel's  process  for  the  Determination  of  Phosphoric  Acid. 
Analyses  of  Bone,  by  Von  Bibra  and  Berzelius. 
Diseased  Bone.    Analyses  by  Lehmann,  Prosch,  Valentin,  and 
Von  Bibra. 

CHAPTER  X. 

EXAMINATION  OF  MIXED  ANIMAL  FLUIDS.  ....          263 

General  Processes  for  the  detection  of  Fibrin,  Albumen,  Casein, 
Pyin,  Pus,  Mucus,  Gelatine,  Chondrin,  Blood,  Biliary  Mat- 
ter, Urea,  Kreatine,  Inosite,  Kreatinine,  Fat,  Cholesterin, 
and  Serolin,  Milk,  Sugar,  Ammonia,  Uric  Acid,  Taurine, 
Leucine,  and  Tyrosine. 

Systematic  Examination  of  Mixed  Fluids  for  the  proximate 
Constituents  of  Animal  Bodies. 


PART  V.—  THE  DETECTION  OF   POISONS  IN 
ORGANIC  MIXTURES,  &c. 

CHAPTER  I. 

ARSENIC  .......  274 

Identification  of  Arsenious  Acid  when  in  the  pure   state. 

Marsh's  and  Reinsch's  tests.     Examination  of  the  Copper 

and  Hydrochloric  Acid  for  Arsenic. 
Detection  of  Arsenic  in.  Organic  Liquids,  which  are  pretty 

clear  and  homogeneous. 
Electrolytic  test  for  Arsenic. 
Detection  of  Arsenic  in  the  contents  of  a  Stomach,  Vomited 

2* 


XV111  CONTENTS. 


PAGE 

Matters,  &c.,  and  in  the  Tissues  and  other  solid  Organic 

Matters. 

Detection  of  Arsenite  of  Copper  in  Paper  Hangings,  &c. 
Quantitative  Determination  of  Arsenic  in  other  Mixtures. 


CHAPTER  II. 

ANTIMONY  .......  292 

Identification  of  Tartar  Emetic. 

Electrolytic  tests  for  Antimony. 

Detection  of  Antimony  in  the  presence  of  Organic  Matters. 

Quantitative  Determination  of  Antimony. 

CHAPTER  III. 

MERCURY         .......  294 

Detection  of  Mercury  in  Organic  Mixtures. 

Lassaigne's  process   for  identifying  minute   Sublimates   of 

Mercury. 

Electrolytic  tests  for  Mercury. 
Detection  of  Mercury  in  the  Tissues. 

CHAPTER  IV. 

LEAD    .  .  .  .  .  .  .  .298 

Examination  of  Water  suspected  to  contain  Lead. 
Detection  of  Lead  in  Organic  Mixtures  and  in  the  Tissues. 

CHAPTER  V. 

COPPER  .  .  .  .  .  .  .  301 

Detection  of  Copper  in  Organic  Mixtures  and  in  the  Tissues. 
Electrolytic  test  for  Copper. 

Quantitative  Determination  of  Copper  in  any  Organic  Mix- 
ture. 

CHAPTER  VI. 

ZINC    ........  307 

Examination  of  Organic  Matters  for  Zinc. 

CHAPTER  VII. 

IODINE  .  .  .  .  .  .  .  309 

Detection  of  free  and  combined  Iodine  in  Organic  Mixtures. 


CONTENTS.  XIX 

CHAPTER  VIII. 

PACK 

SULPHURIC  ACID  ......  311 

Detection  of  Sulphuric  Acid  in  Organic  Mixtures  ;  and  in 

Stains  on  Clothing. 
Detection  of  "  Sulphate  of  Indigo"  in  Organic  Mixtures. 

CHAPTER  IX. 

HYDROCHLORIC  ACID     ......  313 

Detection  of  Hydrochloric  Acid  in  Organic  Mixtures. 
Quantitative  Determination  of  Hydrochloric  Acid. 

CHAPTER  X. 

NITRIC  ACID     .......  315 

Examination  for  Nitric  Acid  in  Organic  Mixtures;  and  in 
Stains  on  Clothing. 

CHAPTER  XL 

OXALIC  ACID    .......  317 

Separation  of  Oxalic  Acid  from  Organic  Mixtures.  Identifi- 
cation and  Quantitative  Determination. 

CHAPTER  XII. 

HYDROCYANIC  OR  PRUSSIC  ACID  .  .  .  .  319 

Detection  of  Hydrocyanic  Acid  in  Organic  Mixtures.     Tests 
applicable  to  the  Vapor.     Liebig's  test.     Henry  and  Hum- 
bert's test.     Prussian  Blue  test. 
Quantitative  Determination  of  Hydrocyanic  Acid. 

CHAPTER  XIII. 

OPIUM  .......  325 

Examination  of  Organic  Mixtures  and  Tissues  for  Morphia 
and  Meconic  Acid.  Identification  of  Morphia. 

CHAPTER  XIV. 

STRYCHNIA       .......  328 

Processes  for  the  detection  of  Strychnia  in  Organic  Mixtures, 
Tissues,  &c.  Extraction  of  Strychnia  by  Kther,  Chloro- 
form, and  Benzole. 


XX  CONTENTS. 

CHAPTER  XV. 

PAGE 

NICOTIA  .......  330 

Extraction  of  Nicotia  from  Organic  Mixtures.     Identification. 

CHAPTER  XVI. 

PHOSPHORUS     .  .  .  .  .  .  •  331 

Detection  of  Unoxidized  Phosphorus  in  Organic  Mixtures. 
Examination  for  Phosphorous  Acid  resulting  from  the 
Oxidation  of  the  Phosphorus. 

CHAPTER  XVII. 

ALCOHOL  .......  333 

Extraction  of  Alcohol  from  Organic  Mixtures ;  its  Identifica- 
tion. 

CHAPTER  XVIII. 

GENERAL   SYSTEMATIC  COURSE  FOR  THE  DETECTION  OF  POISONS  IN 
ORGANIC  MIXTURES  .....  334 

1.  The  Poison  is  believed  to  be  Metallic.    Systematic  Exami- 
nation for  Arsenic,  Antimony,  Mercury,  Copper,  Lead,  Zinc, 
Barium,  Silver,  Bismuth. 

2.  The  Poison  is  believed  to  be  Organic.     Systematic  Exami- 
nation for  Oxalic  Acid,  Morphia,  Strychnia,  Nicotia,  and 
Conia. 

3.  Nothing  is  known  of  the  Nature  of  the  Poison. 

CHAPTER  XIX. 

SEPARATION  OF  POISONS  FROM  ORGANIC  MIXTURES  BY  DIALYSIS.  339 

WEIGHTS  AND  MEASURES.         .....  341 

INDEX  .  343 


LIST  OF  ILLUSTRATIONS 


PAOK 

1.  Oxalate  of  Urea      ......  30 

2.  Nitrate  of  Urea       ......  30 

3.  Uric  Acid    .......  32 

4.  Hippuric  Acid         ......  35 

5.  Mucus  and  Epithelium        .....  38 

6.  Evaporated  Residue  of  Healthy  Urine        ...  42 

7.  Mixed  Phosphates  ......  44 

8.  Prismatic  Crystals  of  Triple  Phosphate      .  .             .  45 

9.  Penniform  Crystals  of  Triple  Phosphate    ...  45 

10.  Stellate  Crystals  of  Triple  Phosphate         ...  46 

11.  Urate  of  Ammonia  .....  C5 

12.  "  "           with  Spicula?     .             .             .             .66 

13.  "      of  Soda          ......  67 

14.  Crystallized  Phosphate  of  Lime      ....  70 

15.  Fermentation  Test  for  Sugar  .             .           •            .  76 

16.  Torula  Vesicles        ......  78 

17.  "       Stem  ......  78 

18.  Fibrinous  Cast         ......  82 

19.  Blood  in  Urine         ......  83 

20.  Pus  in  Urine  ......  85 

21.  Large  Organic  Globules       .....  86 

22.  Small  Organic  Globules       .....  86 

23.  Spermatozoa  and  Spermatic  Granules         ...  88 


XX11  LIST    OF    ILLUSTRATIONS. 

FIGURE.  PA'iK 

24.  Octoliedra  of  Oxalate  of  Lime        ....  90 

25.  "  "  "       seen  when  dry         .  .  90 

26.  Duinb-bells  of  Oxalate  of  Lime      .  .  .  .91 

27.  Rosettes  of  Cystine  .....  92 

28.  Hexagonal  Crystals  of  Cystine       .  .  ...  92 

29.  Chloride  of  Sodium  simulating  Cystine     ...  92 

30.  Nitrate  of  Urea       .  ...  .  .  .95 

31.  Pipette         .......          98 

32.  Burette        .......          98 

33.  Leconte's  Apparatus  for  determining  Urea  .  .         101 

34.  Crystalline  Forms  of  Uric  Acid      .  .  .  .104 

35.  "  "  "  105 

36.  Chloride  of  Sodium  .....         107 

37.  Hippuric  Acid          ......         108 

38.  Mixed  Phosphates  ,  .  .  .  .  .112 

39.  Pus  Corpuscles        .....  117 

40.  Urinorneter .  .  .  .  .  .123 

41.  Triple  Phosphate  (Stella?)  .  .  .  .  .133 

42.  "  "  (Prismatic)          .  .  .  .133 

43.  Crystalline  Forms  of  Uric  Acid      .  .  .  .133 

44.  Octohedra  of  Oxalate  of  Lime        .  .  .  .133 

45.  Dumb-bells  of  Oxalate  of  Lime      .  .  .  .133 

46.  Rosettes  of  Cystine  .  .  .  .  .134 

47.  Hexagonal  Plates  of  Cystine          .  .  .  .134 

48.  Urate  of  Soda          ......         135 

49.  Fat  in  Urine  .  .  .  .  .135 

50.  Mucus  and  Epithelium       .  .  .  .  .135 

51.  Pus  in  Urine  .  .  .  .  .  .135 

52.  Blood  in  Urine         ......         135 

53.  Spermatozoa,  &c.     ......        135 

54.  Apparatus  for  the  Estimation  of  Sugar  in  Urine    .  .         138 

55.  Alternating  Calculus  .  .  .  .  .151 

56.  Uric- Acid  Calculus  .  .  .  .  .151 

57.  Urate  of  Ammonia  Calculus  .  .  .  .153 


LIST    OF    ILLUSTRATIONS.  XXiil 


58.  Phosphate  of  Lime  Calculus  .  .  .  1  •">  I 

59.  Fusible  Calculus     ......         i:>6 

60.  Oxalate  of  Lime  Calculus  ..... 

61.  Biliary  Calculi         ......         1<  3 

62.  Cholesterin  .  .  .  .  .  .         1C4 

63.  Blood  Corpuscles  in  strings  ....         172 

64.  "  "  detached  .  .  .  .172 

65.  "  "  collapsed  .  .  .  .174 

66.  White  Corpuscles  of  the  Blood       .  .  .  .178 

67.  Fat  in  Blood  ....  .215 

68.  Cholesterin  .......        216 

69.  Milk  Globules          ......        227 

70.  Colostrum  Corpuscles          .  .        228 

71.  Pus  in  Milk  ......         235 

72.  Blood  in  Milk  ......        235 

73.  Starch  Granules       ......        237 

74.  Pus  Corpuscles        .  .  ...  .251 

75.  Apparatus  for  the  Estimation  of  Carbonic  Acid      .  .         260 

76.  Arsenious  Acid        ......         275 

77.  Crust  of  Reduced  Arsenic  .  .  .  .276 

78.  Apparatus  for  Marsh's  Test  .  .277 
70.            "                  ""....         278 

80.  Small  Marsh's  Apparatus  for  Minute  Testing         .  .         279 

81.  Electrolytic  Apparatus         .  .284 

82.  Apparatus  for  Dialysis         .  .  .  .  .339 


MEDICAL  CHEMISTRY, 


PART  I. 

CHAPTER    I. 
HEALTHY    URINE 


SECTION  I. 

1.  HEALTHY  human  urine  is  an  amber-colored,  watery 
fluid,  holding  in  solution  a  great  variety  of  substances, 
both  organic  and  inorganic,  and  containing  also  in  sus- 
pension a  small  quantity  of  mucus,  derived  from  the 
bladder  and  urinary  passages.  The  specific  gravity 
(278)  of  the  healthy  secretion  may  be  said  to  vary  from 
1003  to  1030,  depending  on  the  amount  of  solid  and 
liquid  food  taken,  the  period  of  the  day  at  which  the 
urine  is  passed,  and  other  circumstances  which  tend  to 
increase  or  diminish  the  proportion  of  solid  matter  con- 
tained in  it.  Thus  the  urine  which  is  passed  shortly 
after  drinking  much  water  or  other  fluid,  commonly 
called  urina  potus,  is  usually  pale  in  color,  and  of  low 
specific  gravity,  varying  from  1003  to  1009 ;  while,  on 
the  other  hand,  that  which  is  secreted  soon  after  the 
digestion  of  a  full  rneal,  commonly  called  urina  chyli, 
has  most  commonly  a  high  specific  gravity,  frequently 
1030 ;  the  urine  which  is  passed  immediately  after  a 
night's  rest,  called  urina  sanguinis,  may  generally  be 
considered  to  furnish  a  fair  specimen  of  the  average 
3 


26  HEALTHY    UKINE. 

density  of  the  whole  urine,  and  will  in  most  cases  be 
found  to  have  a  specific  gravity  varying  from  1015  to 
1025.  The  average  density  of  the  whole  urine  passed 
by  an  individual  in  the  twenty-four  hours  is  usually  from 
1015  to  1020 ;  and  the  quantity  passed  during  the  same 
period  varies  from  twenty  to  forty-eight  or  fifty  ounces, 
holding  in  solution  usually  from  600  to  700  grains  of 
solid  matter  (279). 

2.  While  warm,  urine  has  a  slightly  aromatic  smell, 
which  is  not  perceptible  after   cooling.     It   is   usually 
slightly  acid  to  test-paper,  from   the   presence   of  acid 
phosphate  of  soda  (NaO,2HO,P05),  but  the  experiments 
of  Dr.  Bence  Jones  show  that  when  passed  shortly  after 
eating,  the  urine  is  often  neutral,  or  even  alkaline,  be- 
coming again  gradually  more  and  more  acid,  up  to  the 
time  when  the  next  meal  is  taken.    When  kept  for  some 
little  time,  it  first  becomes  a  little  more  acid  (apparently 
from  the  formation  of  a  little  lactic  and  acetic  acids),  and 
deposits  a  few  crystals  of  uric  acid  entangled   in    the 
cloudy  deposit  of  mucus ;  but  after  a  longer  period  it 
putrefies,  becoming  alkaline  and  ammoniacal,  and  de- 
posits a  sediment  of  earthy  phosphates,  previously  held 
in  solution  by  the  free  acid  (43).     If  the  urine  be  kept 
for  a  still  longer  time,  it  becomes  more  and  more  con- 
centrated by  spontaneous  evaporation,  deposits  minute 
crystals  of  chloride  of  sodium,  phosphates,  and  other 
salts,  and  eventually  becomes  covered  with  a  grayish- 
colored  mould,  containing  minute  fungi  and  animalcules. 

3.  Although  chemists  have  not  yet  succeeded  in  insu- 
lating for  examination  all  the  ingredients  of  urine,  nor 
even  in  ascertaining  the  general  nature  and  character  of 
several  of  the  compounds  which  probably  enter  into  its 
composition,  still  they  have,  by  their  researches,  deter- 
mined what  appear  to  be  the  most  important  of  its  con- 
stituents ;  and  it  is  to  these  only  that  the  student  need 
turn  his  attention,  leaving  the  more  problematical  and 
obscure  parts  of  the  subject  to  be  decided  by  the  future 
labors  of  the  physiological  chemist. 

4.  The  solid  matters  of  the  urine  may  be  said  to  con- 
sist of  the  following — viz.,  Urea;  uric  acid ;  Jnppuric  acid; 
kreatinine  ;  grape-sugar;  vesical  mucus,  and  epithelial  debris  ; 


UREA.  27 

animal  extractive;  ammoniacal  salts;  fixed  alkaline  salts; 
and  earthy  salts* 

5.  The  student  will  do  well  to  test  a  little  of  the  healthy 
secretion,  which  should,  for  this  purpose,  be  that  passed 
immediately  after  a  night's  rest  (1),  for  these  several  sub- 
stances, in  the  manner  described  under  each,  in   the  fol- 
lowing sections ;  and  if  he  has  leisure  and  opportunity, 
he  may  prepare  specimens  of  urea,  uric  and  hippuric 
acids,  and  some  of  the  other  constituents. 

SECTION  II. 
Urea  (CJI4X20,). 

6.  This  important  ingredient  of  the  urine,  which  ap- 
pears to  be  the  vehicle  by  which  nearly  the  whole  of  the 
nitrogen  of  the  exhausted  tissues  of  the  body  is  removed 
from  the  system,  is  a  solid  crystalline  substance,  colorless 
when  in  a  state  of  purity,  and  easily  separated  from  the 
other  matters  with  which  it  is  associated. 

7.  The  presence  of  urea  in  the  urine  may  be  readily 
shown  by  concentrating  a  little  of  the  secretion  to  about 
one-half  or  one-third  its  bulk,  and  mixing  it  with  an 
equal  quantity  of  pure  nitric  acid ;  when  delicate  crys- 
talline rhomboidal  plates  of  impure  nitrate  of  urea  (C2IT4 
N2O2,HO,NOf)  will  be  found  gradually  to  separate  from 
the  liquid  (16). 

8.  Pure  urea  may  be  obtained  from  the  nitrate  thus 
separated.     For   this  purpose,  about   a   pint   of   urine, 
filtered  from  the  mucus  as  soon  as  possible  (11),  is  eva- 
porated, at  a  heat  below  its  boiling  point,  to  two  or  three 
ounces;  when  cool,  the  concentrated  urine  is  decanted 
from  the  deposited  salts,  and  mixed  with  an  equal  bulk 
of  colorless  nitric  acid  (sp.  gr.  1*25).     After  standing  for 
some  time,  the  pasty  mass  of  nitrate  of  urea  is  pressed,  to 
free  it  from  the  adhering  liquid,  dissolved  in  a  little  boiling 
water,  and  allowed  to  crystallize.     The  pure  crystals  are 
again  dissolved  in   hot  water,  and  finely  powdered  car- 
bonate of  baryta  is  added  in  small  portions,  as  long  as 

*  According  to  Campbell,  urino  also  contains  a  minute  quantity  of 
formic  acid  (C2H204). 


28  HEALTHY    URINE. 

any  effervescence  is  perceptible.  The  nitric  ncid  has 
now  combined  with  the  baryta,  whilst  the  carbonic  acid, 
being  incapable  of  combining  with  the  urea,  makes  its 
escape. 

Nitrate  of  urea.          Carb.  baryta.          TTrea.         Nitrate  baryta. 

^2H4N202,HO,N^+l3aO,Ca]  =  C^H4N2<^4-^aO,Nc£-f  HO+CO2. 

The  excess  of  carbonate  of  baryta  is  separated  by 
filtration,  and  the  clear  liquid  evaporated  to  dryness  on 
the  water-bath.  The  dry  residue  of  urea  and  nitrate  of 
baryta  is  boiled  with  a  little  alcohol,  which  dissolves  only 
the  urea,  and,  when  decanted  off  and  evaporated,  deposits 
it  in  prismatic  crystals  resembling  nitre,  which  may  be 
purified,  if  necessary,  by  dissolving  in  water,  decolor- 
izing ^vith  animal  charcoal,  and  evaporating  the  filtered 
solution. 

9.  The  crystals  of  urea,  which,  when  obtained  by  slow 
evaporation,  are  four-sided  prisms,  and  deliquesce  slightly 
in   air,  are  soluble  in  about  their  own  weight  of  cold 
water,  and  in  a  much  smaller  quantity  of  hot;   from 
which  latter  the  urea  separates  on  cooling,  in  the  form 
of  beautiful  silky  needles.     It  is  soluble  in  about  4.5 
parts  of  cold  alcohol,  and  in  less  than  half  that  quantity 
of  hot;  in  cold  ether  it  is  nearly  insoluble.     Its  taste  is 
saline  and  cooling,  somewhat  resembling  that  of  nitre. 

10.  The  proportion   of  urea  present  in  healthy  urine 
appears  to  vary  from  twelve  to  upwards  of  thirty  parts 
in  1000,  about  fourteen  or  fifteen  being  the  average. 

11.  An   aqueous  solution  of  urea  may  be  kept,  pro- 
vided  it  is  pure  and  tolerably  concentrated,  for  a  con- 
siderable length   of  time,  without  undergoing  chemical 
change;  but  if  any  albumen  or  mucus,  or  other  ferment- 
escible  matter,  is  present,  decomposition  rapidly  sets  in, 
and  in  a  short  time   the  whole   of  the    urea   becomes 
transformed  into  carbonate  of  arnmonia(Ar/Z40,Cr02),  the 
elements  of  water  being  at  the  same  time  assimilated. 

C2H4N202  +  4HO  =  2(NH4O,COJ. 

In  urine,  this  change  speedily  takes  place,  Qwing  to  the 
presence  of  mucus;  the  secretion  thus  acquiring,  especially 
in  warm  weather,  an  alkaline  reaction  in  the  course  of  a 


UREA.  29 

few  hours  after  being  passed.  Under  the  influence  of 
the  caustic  alkalies,  also,  urea  becomes  gradually  con- 
verted into  carbonic  acid  and  ammonia. 

12.  When  heated  on  platinum  foil  to  about  250°,  urea 
fuses  without  undergoing  decomposition  ;  but  if  the  heat 
be  increased  much  beyond  that  point,  it  is  decomposed 
into  ammonia  (NH3)  and  carbonate  of  ammonia  (NH4O, 
COJ,  which  volatilize,  leaving  a  residue  consisting  chiefly 
of  melanuric  acid  (C6H4N404). 

13.  Urea,  though  its  solution  is  neutral  to  test-paper, 
has  decidedly  basic  characters,  combining  with  acids  to 
form  salts,  some  of  which  are  crystalline.     Of  these,  the 
two  which  are  of  the  most  practical  importance  are  the 
oxalate  (C2H4N2O2,HO,C203)  and  the  nitrate  (C2H4N2p2, 
HO,N05),  which,  on  account  of  their  sparing  solubility 
in  water,  supply  a  ready  means  _of  separating  urea  from 
the  other  matters  co-existing  in  the  urine. 

14.  Oxalate  of  urea  (C2H4N202,HO,C203)*  may  be  pre- 
pared by  concentrating  urine  on  a  water-bath  to  about 
one-eighth  its  bulk,  and  filtering  through  muslin,  in  order 
to   separate  the  insoluble   sediment  of  phosphates  and 
urates,  which  are  gradually  deposited  during  the  evapora- 
tion.    The  liquid  thus  clarified  is  mixed  with  about  an 
equal  bulk  of  a  strong  solution  of  oxalic  acid  in  hot 
water,  or  the  solid  acid  in  powder  may  be  added  as  long 
as  the  liquid,  heated  to  about  190°  or  200°,  continues  to 
dissolve  it.     The  mixture,  on  cooling,  deposits  an  abun- 
dant crop  of  crystals  of  oxalate  of  urea,  mixed  with  a 
little  of  the  excess  of  oxalic  acid,  and  colored  brown  by 
the  adhering  impurities.     The  crystals  are  then  gently 
pressed   between  folds  of  filtering   paper,  washed  with 
a  small  quantity  of  ice-cold  water,  and  purified  by  re- 
crystallization;   the  last  traces  of  coloring  matter  being 
removed,  if  necessary,  by  boiling  the  solution  with  puri- 
fied animal  charcoal.f 

*  The  bibasic  character  of  oxalic  acid  being  now  generally  recog- 
nized, the  formula  of  oxalate  of  urea  should  be  written  2(C2H4N2Of), 
2HO,C406. 

f  Animal  charcoal  is  purified  from  the  phosphate  and  carbonate  of 
lime  by  repeatedly  boiling  it  with  hydrochloric  acid,  till  the  acid 
liquid  is  not  precipitated  by  ammonia ;  the  charcoal  must  then  be 
washed  with  water  till  the  latter  is  no  longer  acid. 

8* 


so 


HEALTHY    URINE. 


15.  The  oxalate  thus  obtained  is 
colorless,  and  in  the  form  of  tabular 
or  prismatic  crystals  (Fig.  1),  which 
are  readily  soluble  in  hot  water, 
but  only  sparingly  so  in  cold, 
twenty-five  parts  of  which  dissolve 
net  more  than  one  part  of  the  salt. 

The  oxalate  of  urea  obtained 
from  urine  may  be  employed  to 
furnish  pure  urea,  by  dissolving  it 
in  hot  water,  and  adding  powdered  chalk  as  long  as  it 
causes  effervescence.  The  insoluble  oxalate  of  lime  is 
then  filtered  off,  and  the  solution  of  urea  evaporated  on 
a  water-bath  to  crystallization. 


Oxalate  of  Urea. 


Oxalate  of  urea. 


Carb.  lime.        Oxal.  limo. 


Urea. 


C2H4N202,HO,C203  -f-  CaO,C02  =  CaO,C2O3  +  C2H4N202  -f  HO  +  C02. 

16.  Nitrate  of  urea  (C2H4N2O2,HO,N05)  may  be  obtained 
by  adding  strong,  colorless  nitric  acid,  free  from  nitrous 
acid,  to  urine  previously  concentrated  by  -evaporation  to 
about  one-third  its  bulk;  the  nitrate  gradually  separates 
in    irregular    rhomboidal    plates 
Fig-  2.  (Fig.  2),  more  or  less  colored  and 

modified  in  form  by  the  impuri- 
ties present.  The  crystals  are 
washed  with  a  little  ice-cold  water, 
then  pressed  between  folds  of 
filtering  paper,  and  redissolved  in 
lukewarm  water;  lastly,  they  are 
purified  by  recrystallization,  and 
if  necessary,  the  last  traces  of 
coloring  matter  may  be  removed 
by  boiling  the  solution  with  puri- 
fied animal  charcoal. 

The  absence  of  nitrous  acid  in 
the  nitric  acid  employed  for  pre- 
'  mtrate  of  urea.  cipitating  the  urea  is  insisted  on 

because  this  substance  is  imme- 
diately decomposed  by  nitrous  acid,  with  violent  effer- 
vescence, from  escape  of  carbonic  acid  and  nitrogen. 


URIC    (OR    LITHIC)   ACID.  31 

C2H4N,0,  -f  2N03  =  2C02  +  N4  +  4HO. 

Even  with  colorless  nitric  acid,  a  slight  effervescence 
always  takes  place,  since  a  little  nitrous  acid  is  formed 
by  the  action  of  urinary  coloring  matter  upon  the  nitric 
acid. 

17.  Nitrate  of  urea  is  soluble  in  about  eight  times  its 
weight  of  cold  water,  and  in  a  much  smaller  quantity  of 
hot.     It  is  tolerably  soluble  also  in  alcohol,  especially 
when  warm ;  but  almost  insoluble  in  ether. 

18.  The  formation  of  this  crystalline  compound  on  the 
addition  of  nitric  acid,  is  one  of  the  most  distinctive  tests 
for  the  presence  of  urea  which  we  possess.     The  experi- 
ment is  made  easily,  and  with  great  delicacy,  under  the 
microscope,  by  concentrating  a  drop  or  two  of  urine  on 
a  glass  slide,  and  adding  to  it  about  an  equal  quantity  of 
pure  nitric  acid ;  the  nitrate  will  gradually  crystallize  in 
delicate    rhomboidal    plates   (Fig.    2),  the    number   and 
abundance  of  which  will  furnish  some  indication  of  the 
quantity  of  urea  present  in  the  secretion  (181). 


SECTION  III. 
Uric  (or  Lithic)  Acid  (Ol(}H,N4Ot. 

19.  Uric  acid,  though  usually  present  only  in  small 
quantity  in  human  urine,  appears  to  be  one  of  the  most 
important  of  its  ingredients ;  and  as  the  proportion  varies 
considerably  in  many  forms  of  disease,  its  determination, 
when   in    abnormal   quantity,   frequently   affords   much 
valuable  assistance  to  the  physician  in  diagnosis.     The 
proportion   present  in  the  healthy  secretion  appears  to 
vary  from  OS  to  nearly  I/O  in  1000  parts,  about  0*4  being 
the  usual  average.     It  probably  exists,  for  the  most  part, 
in  combination  with  alkalies,  since,  when  uncombined,  it 
requires  nearly  15,000  times  its  weight  of  cold  water  to 
dissolve  it,  while  the  alkaline  n rates  are  considerably 
more  soluble  (22). 

20.  Uric  acid  may  be  obtained  by  adding  to  urine,  pre- 
viously concentrated  to  about  half  its  bulk,  a  few  drops 
of  hydrochloric  acid  (IIQI\  and  allowing  the  mixture  to 


32  HEALTHY    URINE. 

stand  for  a  few  hours  in  a  cool  place.*     Minute  reddish 
crystals  of  the  acid  gradually  appear,  having  the  forms 
shown  in  Fig.  3,  stained  with  the  coloring  matters  co- 
existing in  the  urine.  These  crystals  may  then  be  dissolved 
in    moderately   dilute    potash,    and 
Fig-  3-  from  the  solution  thus  obtained  the 

pure  acid  may  be  again  precipitated 
in  a  crystalline  and  colorless  state, 
by  supersaturating  it  with  hydro- 
chloric acid. 

21.  The  crystalline  forms  in  which 
uric  acid  is  presented  to  us  are  very 


<r~v  ^^        various  (186),  but  they  all  appear  to 
^*         0  be    modifications    of    the    rhombic 

uric  Add.  prism.    Most  of  these  crystals,  when 

examined  with  the  polarizing  micro- 
scope, develop  very  beautiful  colors ;  and  their  forms  are 
frequently  characteristic,  and  indicative  of  the  peculiar  cir- 
cumstances under  which  they  may  have  been  deposited. 

22.  Uric  acid  requires,  according  to  Liebig,  about 
15,000  times  its  weight  of  cold,  and  nearly  2000  times 
its  weight  of  hot  water  to  dissolve  it,  forming,  in  the 
latter,  a  solution  which  is  feebly  acid  to  test-paper.  It 
is  insoluble  in  alcohol,  and  nearly  so  in  dilute  hydro- 
chloric and  sulphuric  acids;  it  dissolves  in  the  latter  acid 
when  concentrated,  and  is  reprecipitated  on  the  addition 
of  water.  It  combines  with  bases,  especially  the  alkalies 
and  alkaline  earths,  forming  salts  (urates),  which  are  for 
the  most  part  insoluble,  or  very  sparingly  soluble  in 
water.  Of  these  the  most  soluble  is  the  urate  of  potash 
(2KO,CIOH2N4O4),  which  dissolves  in  about  35  times  its 
weight  of  hot  water.  On  this  account,  uric  acid  dissolves 
with  comparative  facility  in  a  dilute  solution  of  potash. 
Urate  of  soda  (2NaO,Ci0H2N404)  requires  for  its  solution 
124  times  its  weight  of  hot  water;  and  urate  of  ammonia 
(NII40,HO,C]0II2N404)  243  times  its  weight  of  hot,  and 
about  1720  of  cold  water,  to  effect  its  solution.  The 
presence  of  a  small  quantity  of  chloride  of  sodium,  such 

*  Even  without  previous  concentration,  urine  will  generally  deposit 
crystals  of  uric  acid,  if  mixed  with  a  little  hydrochloric  acid  and  set 
aside. 


11IPPURIC    ACID.  33 

as  is  contained  in  tbe  urine,  renders  water  capable  of 
dissolving  nearly  twice  as  much  urate  of  ammonia  as  is 
taken,  up  by  pure  water.* 

23.  The  action  of  nitric  acid  (IIO,NO^  upon  uric  acid 
is  highly  characteristic,  and  furnishes,  perhaps,  the  most 
delicate  test  of  its  presence  which  we  possess.     If  a  little 
of  the  acid,  in  the  state  of  powder,  is  placed  in  a  drop  or 
two  of  tolerably  strong  nitric  acid,  in  a  watch  glass  or 
on  a  strip  of  glass,  it  will  gradually  dissolve;  carbonic 
acid  (C02)  and  nitrogen  being  given  off  with  efferves- 
cence, and  leaving  behind  a  mixture  of  alloxanf  (CSII4 
-^2^10)*  alloxantine  (G^H^N^O^  urea,  and   some   other 
compounds.     This   may  then   be   evaporated    nearly  to 
dry  ness  at  a  gentle  heat,  when  a  red  residue  will  be  left, 
which,  when  cold,  should  be  moistened  by  a  drop  or  two 
of  ammonia,  or  exposed  to  amrnoniacal  fumes,  which  will 
develop  a  beautiful  purplish-red  color,  owing  to  the  for- 
mation of  murexide  ((712£r6/V508).     If  the  mass  be  now 
moistened  with  solution  of  potash,  a  very  beautiful  purple 
color  will  be  produced.     The  potash  may  be  applied  at 
once  to  the  residue  left  after  evaporating  the  nitric  acid, 
and  is  a  far  more  delicate  and  characteristic  test  than  the 
ammonia.     The  same  effect  is  produced  when  urate  of 
ammonia,  or  any  other  urate,  is  similarly  treated. 

24.  When   heated  before  the  blowpipe,  uric  acid  is 
decomposed,  emitting  a  disagreeable  smell,  resembling 
that  of  burnt  feathers,  mixed  with  that  of  hydrocyanic 
acid,   which,  together  with  carbonate  of  ammonia  and 
some  other  compounds,  is  formed  during  the  decompo- 
sition. 

SECTION  IV. 

Hippuric  Acid  (HO,C18IISN05). 

25.  A  small  quantity  of  hippuric  acid  appears  to  be 
generally  present  in  healthy  urine,  and  in  certain  forms 
of  disease,  especially  in  cases  where  a  vegetable  diet  has 

*  Lithia  forms  one  of  the  most  soluble  urates.  Schilling  has  shown 
that  the  acid  urate  of  lithia  (LiO,HO,C10H2N4O4)  dissolves  in  39  parts 
of  boiling  water,  and  368  parts  of  cold  water.  The  neutral  urate 
would  be  still  more  soluble. 

f  Alloxan  has  been  found  by  Liebig,  on  one  occasion,  in  mucus 
from  the  intestines. 


34:  HEALTHY    URINE. 

been  adopted,  the  quantity  is  found  to  increase  consider- 
ably.* In  jaundice,  according  to  Kiihne,  hippuric  acid 
is  entirely  absent  from  the  urine,  even  after  the  adminis- 
tration of  benzoic  acid,  which  is  converted  in  the  normal 
state  of  the  system,  into  hippuric  acid. 

26.  Hippuric  acid  may  be  prepared  from  fresh  human 
urine,  or  still  more  readily  from  the  urine  of  the  herbivora, 
which  usually  contains  it  in  much  larger  quantity  than 
the  human  secretion.  The  urine  is  first  evaporated  at  a 
gentle  heat  until  it  has  the  consistence  of  a  syrup ;  it  is 
then,  after  cooling,  supersaturated  with  hydrochloric  acid, 
which  will  dissolve  the  earthy  salts,  and  cause  after  a 
time  a  crystalline  precipitate  of  impure  hippuric  acid 
mixed  with  uric  acid,  coloring  matters,  and  other  sub- 
stances, which  give  a  more  or  less  dark  brown  or  reddish 
color.  The  precipitate  is  then  dissolved  in  a  small 
quantity  of  hot  water,  from  which  it  again  crystallizes 
on  cooling.  To  obtain  the  pure  acid,  these  crystals  may 
be  boiled  with  hydrate  of  lime  and  water,  the  solution 
of  hippurate  of  lime  (CaO,C18H8N05),  filtered  and  mixed 
with  excess  of  hydrochloric  acid,  which  precipitates  the 
hippuric  acid,  in  the  form  of  minute  tufts  of  needle-shaped 
crystals  (Fig.  4,  a  and  6);  these  may  be  again  dissolved  in 
hot  water,  and  allowed  to  cool  gradually,  when  beautiful 
crystals  (four-sided  prisms),  will  be  obtained  of  consider- 
able length,  but  so  friable,  as  to  fall  into  powder  under 
the  slightest  pressure.  A  more  minute  examination  for 
hippuric  acid  in  human  urine  may  be  made  by  evapo- 
rating eight  or  ten  ounces  of  urine  to  a  syrup,  acidulating 
with  hydrochloric  acid,  and  agitating  with  about  an 
equal  volume  of  ether,  the  separation  of  which  is  after- 
wards promoted  by  adding  a  little  alcohol.  If  the  solution 

*  According  to  Liicke,  hippuric  acid  is  often  entirely  absent  from 
the  urine  of  persons  living  upon  a  mixed  diet,  and  can  only  be  detected 
when  the  food  is  composed  chiefly  of  vegetables.  It  is  said  to  increase 
in  fever,  in  chorea,  and  in  diabetes.  Dr.  Bence  Jones  has  recently 
determined  the  hippuric  acid  in  the  urine  of  two  healthy  men  living 
upon  a  mixed  diet.  A  large  number  of  experiments  led  to  the  mean 
result  that,  in  one  case,  the  urine  of  24  hours  (1-25  pint)  contained 
4-96  grs.  of  hippuric  acid,  and  in  the  other  (2-37  pints)  6-5  grs.,  tfce 
quantities  of  uric  acid  passed  in  the  same  time  being,  respectively, 
4-74  and  11-6  grs. 


HIPPUBIC    AC1I>.  35 

in  ether  be  evaporated,  and  the  residue  boiled  with  a 
little  water,  the  hippuric  acid  will  be  dissolved,  and  de- 
posited in  crystals,  when  the  solution  is  allowed  to  stand. 

Fig.  4. 


Hippuric  Acid. 

27.  Ilippuric  acid  is  very  sparingly  soluble  in  cold 
water,  requiring  ajbout  400  times  its  weight  to  dissolve 
it;  in  hot  water,  however,  it  is  readily  soluble,  and,  on 
cooling,  crystallizes  in  beautiful  silky  tufts.     It  is  very 
soluble  in  alcohol,  but  very  slightly  in  ether.* 

28.  When  mixed  with  uric  acid,  it  may  be  separated 
from  that  substance  by  treating  the  mixture  either  with 
hot  water  or  alcohol,  in  both  of  which  uric  acid  is  in- 
soluble or  nearly  so  (22).     It  may  be  distinguished  from 
uric  acid  also,  by  its  giving  no  purple  color  when  tested 
with  nitric  acid  and  ammonia  (23),  and  by  its  different 
crystalline  form  (26,  29,  186). 

29.  When  an  alcoholic  solution  of  hippuric  acid  is 
allowed  to  evaporate  slowly,  the  crystalline  residue  which 
is  left  has  usually  some  such  appearance  as  that  shown 
in  Figure  4,  c.     When  deposited  from  a  hot  aqueous 
solution,  the  crystals  have  more  the  appearance  shown 
at  d  in  the  figure. 

30.  When  heated  in  a  tube,  it  is  converted  chiefly  into 
benzoic  acid  (HO,C14H5O3),  and   benzoate   of  ammonia 
(NH40,C14H503),  which  sublime,  together  with  a  red  oily 
matter  (benzonitrile,  C14H5N),  which  has  a  peculiar  and 
characteristic  smell,  resembling  that  of  the  Tonka  bean. 

*  Thus  distinguished  from  benzoic  acid,  which  dissolves  readily  in 
ether. 


36  HEALTHY    URINE. 

When  boil.ed  with  acids  or  alkalies,  hippuric  acid  is  con- 
verted into  benzoic  acid  and  glycocine  (gelatine  sugar) : 

Hippuric  acid.  Beuzoic  acid.          Glycocine. 


HO,C18H8N05  +  2HO  =  HO,C14H5O3  -f  C4H5N04. 

SECTION    V. 
Kreutinine  (CbH7N30.). 

30  a.  This  substance  is  contained  in  healthy  human 
urine,  in  the  proportion  of  about  0.4  in  1000  parts,  and 
in  larger  quantity  in  cow's  urine,  and,  although  its  phy- 
siological and  pathological  relations  have  not  yet  been 
fully  investigated,  it  must  be  regarded  as  a  very  import- 
ant constituent  of  the  excretion. 

In  order  to  extract  the  kreatinine,  a  pint  of  urine  is 
neutralized  with  milk  of  lime,  and  chloride  of  calcium 
is  added  as  long  as  it  causes  a  fresh  precipitate.  The 
earthy^  phosphates  are  then  separated  by  filtration,  and 
the  clear  liquid  evaporated  on  a  water-bath  to  a  small 
bulk,  so  that  the  salts  begin  to  crystallize  out  on  cooling. 
After  it  has  been  allowed  to  stand  for  some  time,  the 
liquid  is  poured  off*  into  another  vessel  (leaving  the  de- 
posit), mixed  with  about  ^th  of  a  saturated  solution  of 
chloride  of  zinc,  well  stirred  with  a  glass  rod,  and  set 
aside  for  three  or  four  days.  A  crystalline  precipitate 
will  then  be  deposited,  consisting  of  a  compound  of 
kreatinine  with  chloride  of  zinc  (C8H7N3O2,ZnCl).  This 
is  washed  two  or  three  times  with  small  quantities  of 
cold  water,  and  dissolved  in  boiling  water.  The  solution 
is  boiled  in  a  dish,  and  freshly  prepared  hydrated  oxide 
of  lead*  added  in  small  portions,  till  a  yellow  precipitate 
(oxychloride  of  lead)  has  separated,  and  the  solution  is 
decidedly  alkaline.  The  kreatinine  is  thus  set  free  and 
dissolved  by  the  water,  whilst  the  chloride  of  zinc  is 
decomposed  by  the  hydrated  oxide  of  lead,  with  produc- 
tion of  hydrated  oxide  of  zinc  and  oxychloride  of  lead, 
which  are  both  insoluble  in  water.  The  filtered  liquid 

*  Prepared  by  precipitating  nitrate  of  lead  with  a  slight  excess  of 
potash,  and  rapidly  washing,  on  a  filter,  so  long  as  the  washings  are 
strongly  alkaline. 


KUEATININK.  37 

is  boiled  with  a  little  animal  charcoal,  which  removes 
the  coloring  matter,  as  well  as  any  oxide  of  lead  which 
may  have  dissolved,  and  after  a  second  filtration  is  evapo- 
rated to  dryness  on  the  water-bath.  On  treating  the 
residue  with  hot  alcohol,  the  kreatinine  is  dissolved,  and 
may  be  obtained  in  beautiful  transparent  prisms,  by 
allowing  the  alcohol  to  evaporate.  The  portion  left  un- 
dissolved  by  the  aleohol  generally  contains  kreatine 
(C8II9N304),  a  feeble  organic  base,  which  is  found  in  the 
juice  of  flesh.  It  was  formerly  thought  that  the  kreatine 
was  also  a  constituent  of  urine,  but  recent  experiments 
have  shown  it  to  be  formed  from  the  kreatinine,  during 
the  evaporation  of  the  urine,  by  the  assimilation  of  the 
elements  of  water : 

Kroatiniue.  Kreatine. 

C8H^tOf  -f  2HO  ='c8H9N3o7 

Since  this  change  takes  place,  even  in  the  cold,  in  alkaline 
solutions,  the  urine  should  be  filtered  as  rapidly  as  pos- 
sible after  the  addition  of  milk  of  lime,  and  a  large  excess 
of  the  latter  should  be  avoided. 

Kreatinine  forms  brilliant  prismatic  crystals,  which 
dissolve  in  twelve  parts  of  cold,  and  in  a  smaller  propor- 
tion of  hot  water  or  of  alcohol.  The  solution  is  alkaline 
to  test-papers,  and,  even  though  moderately  dilute,  yields 
a  characteristic  crystalline  precipitate  with  solution  of 
chloride  of  zinc,  especially  on  stirring.  It  combines 
with  acids  to  form  crystalline  salts. 

Quantitative  determination  of  kreatinine  in  urine. — In 
order  to  determine  the  quantity  of  kreatinine  in  urine, 
the  process  given  above  requires  some  modification.  The 
following  is  the  method  adopted  by  Neubauer  for  the 
estimation  of  kreatinine  in  the  form  of  the  double  com- 
pound with  chloride  of  zinc. 

About  5000  grs.  of  urine  are  rendered  slightly  alkaline 
with  milk  of  lime,  and  chloride  of  calcium  is -added  as 
long  as  any  fresh  precipitate  is  formed.  The  filtered 
liquid  is  evaporated  nearly  to  dryness  on  the  water-bath, 
and  mixed,  while  still  warm,  with  about  an  ounce  of 
strong  alcohol  (95  per  cent.) ;  the  mixture  is  rinsed  into 
a  beaker,  set  aside  for  four  or  five  hours  and  filtered,  the 
4 


38 


HEALTHY    UEINE. 


residue  upon  the  filter  being  washed  with  alcohol.  The 
filtrate  and  washings  are  evaporated  to  about  one  and  a 
half  ounce,  and  mixed  with  a  small  quantity  of  a  very 
strong  alcoholic  solution  of  chloride  of  zinc.  After  being 
briskly  stirred,  the  mixture  is  set  aside  for  three  or  four 
days,  when  the  crystalline  compound  of  kreatinine  with 
chloride  of  zinc  may  be  collected  on  a  weighed  filter, 
washed  with  alcohol,  and  dried  at  212°.  From  the 
weight  of  the  precipitate,  that  of  the  kreatinine  may  be 
found  by  the  proportion : 


Ate.  wt.  of  kreatinine        Ate.  wt,  of 
aud  chloride  of  zinc.          kreatiiie. 


181 


113 


weight  of  precipitate     :     x 


SECTION  VI. 


Fig.  5. 


Vesical  Mucus  and  Epithelial  Scales. 

31.  The  small  traces  of  mucus  and  epithelial  debris, 
which  are  always  present  in  urine,  and  which  do  not 
generally  amount  to  more  than  from  0.1  to  0.3,  in  1000 
parts  of  the  healthy  secretion,  are  derived  from  the  in- 
ternal surface  of  the  bladder  and  urinary  passages.  The 
quantity  is  so  small  as  to  be  scarcely  visible  in  healthy 
urine,  until,  after  standing  a  short  time,  it  has  subsided, 
in  the  form  of  a  thin  cloud,  to  the  bottom  of  the  liquid. 

It  may  be  separated  by  passing 
the  urine  through  a  filter,  on 
the  sides  of  which  it  will  be 
deposited  in  the  form  of  a  shin- 
ing pellicle. 

32.  When  examined  under 
the  microscope,  mucus  is  found 
to  consist  of  minute  granular 
corpuscles  (Fig.  5,  a)  floating 
in  the  fluid,  which  are  color- 
less, or  nearly  so,  more  or  less 
round,  and  frequently  oval  in 
shape,  and  usually  accompa- 
nied by  epithelial  scales.  The 
mucus  corpuscles  dissolve  when  treated  with  strong  nitric 
and  acetic  acids,  forming  a  solution  from  which,  after 


Mucus  Corpuscles  and  Scales  of  Epi- 
thelium.    Magnified  200  diameters. 


EXTRACTIVE    MATTER.  39 

boiling,  ferrocyanide  of  potassium  throws  down  a  white 
precipitate. 

33.  When  treated  with  dilute  acetic  acid  (//0,(74ZT303), 
these  corpuscles   become   more   transparent,   lose   their 
granular  appearance,  and  show  in   the  interior  one  or 
more  distinct  nuclei  (662).   The  corpuscles  are  unaffected, 
or  nearly  so,  by  the  dilute  mineral  acids,  but  readily  dis- 
solve in  a  solution  of  potash.     For  the  further  characters 
of  mucus,  see  paragraphs  99,  153,  210,  247,  660,  &c. 

34.  The  epithelial  scales  found  in  the  urine,  associated 
with  mucus,  and  derived  from  the  epithelial  covering  of 
the  organs  through  which  the  secretion  has  passed,  are 
usually  more  or  less  torn  and  broken  (Fig.  5),  but  are 
occasionally  met  with  uninjured,  when  they   have  the 
appearance  shown  at  b  in  the  figure. 

SECTION  VII. 
Extractive  Matter. 

35.  The  term  extractive  matter  is  usually  applied  to 
those  organic  constituents  of  animal  fluids,  the  nature  of 
which  cannot  be  exactly  defined,  and  its  use  therefore 
becomes  more  restricted  in    proportion  as  analysis  ad- 
vances.    Thus,  within  the  last  few  years,  the  analyses  of 
urine    have   disclosed,    among    the   extractive   matters, 
minute  proportions  of  two  substances,  which  are  also 
found    in    the  juice   of    muscular   flesh,    viz.,    kreatine 
(C8H9N3O4),  and  kreatinine  (C8H7N302),  as  well  as  a  little 
grape-sugar.*     The  peculiar  yellow  coloring  matter  of 
the  urine  is  also  included  under  the  head  of  extractive 
matters,  together  with  minute  quantities  of  fatty  acids. 

36.  In  stating  the  results  of  an  analysis  of  urine,  it  is 
usual  to  distinguish  between  the  alcoholic  extractive  mat- 
ters, which  are  soluble  in  alcohol,  and  the  watery  extrac- 
tive^ which  will  dissolve  only  in  water.   The  former  aver- 
ages about  twelve  parts  in  1000  of  normal  urine,  whilst 
the  watery  extract  amounts  to  only  two  or  three  parts. 

*  Dr.  Bence  Jones  (Quart.  Jour.  Chem.  Soc.,  April,  1861)  has  ob- 
tained as  much  as  two  grains  of  grape-sugar  from  forty  ounces  of 
healthy  urine. 


40  HEALTHY    URINE. 

The  real  nature  of  these  matters  is  still  very  imperfectly 
understood;  and  until  we  shall  have  obtained  further 
insight  into  them  and  their  connection  with  the  animal 
functions,  the  student  may  consider  them  as  so  much  un- 
defined matter  excreted  from  the  body;  without  waiting 
to  inquire  whether  lactic  acid  and  other  compounds,  the 
presence  of  which  may  at  present  be  considered  as  uncer- 
tain, are  or  are  not  contained  in  it. 

Coloring  matters  obtained  from  urine. — The  yellow  color- 
ing matter  of  urine  is  characterized  by  the  purple  color 
which  it  gives  when  heated  with  concentrated  hydrochlo- 
ric acid.  A  peculiar  red  coloring  matter  containing  iron, 
and  very  similar  in  its  character  to  the  coloring  matter  of 
the  blood,  has  been  extracted  from  urine*  by  the  follow- 
ing process:  The  urine  was  evaporated  to  a  syrup,  and 
treated  with  alcohol ;  the  alcoholic  solution  boiled,  and 
gradually  mixed  with  milk  of  lime,  until  it  was  decolor- 
ized. The  precipitate  containing  the  coloring  matter  in 
combination  with  lime  was  filtered  off  and  washed  suc- 
cessively with  water  and  ether;  it  was  then  dried  and 
treated  with  a  mixture  of  hydrochloric  acid  and  alcohol, 
by  which  the  coloring  matter  was  dissolved.  By  shaking 
the  alcoholic  solution  with  an  equal  volume  of  ether  during 
several  days,  the  coloring  matter  was  obtained  in  ethereal 
solution,  and  after  washing  the  latter  with  water,  and 
evaporating,  was  left  as  a  dark  red  mass,  consisting  of  the 
uroluxmatin  accompanied  by  a  resinous  substance. 

Several  observers  have  recorded  the  occasional  presence 
of  a  blue  coloring  matter  in  urine,  as  well  as  the  existence, 
in  other  cases,  of  some  substance  which  gave  rise  to  the 
separation  of  an  insoluble  blue  matter,  when  the  urine 
was  mixed  with  sulphuric  or  hydrochloric  acid  and  al- 
lowed to  stand.  Dr.  Hassall  showed  that  this  substance 
corresponded,  in  its  properties,  to  ordinary  indigo-blue, 
and  the  more  recent  experiments  of  Schunck  have  demon- 
strated the  existence  in  most  specimens  of  healthy  urine 
of  a  substance  possibly  identical  with  the  indican  existing 
in  woad,  which  is  resolved,  by  the  action  of  strong  acids, 

*  Harley,  Journ.  Fr.  Chem.,  xliv.  264. 


AMMONIACAL    SALTS.  41 

into  sugar  and  indigo-blue  (0lflII5NO2).*  Indigo  was  ob- 
tained from  most  of  the  samples  of  healthy  urine  by  the 
following  process:  sixteen  ounces  of  urine  are  mixed  with 
tribasic  acetate  of  lead  in  excess,  and  filtered.  The  filtered 
liquid  is  mixed  with  an  excess  of  ammonia,  the  precipi- 
tate collected  and  decomposed  with  cold  dilute  sulphuric 
acid.  The  solution  is  again  filtered  and  set  aside,  when  it 
deposits  a  blue  precipitate.  If  this  be  filtered  off,  washed 
with  a  little  caustic  soda,  and  then  with  boiling  alcohol, 
the  latter  dissolves  a  purple-red  coloring  matter,  which 
resembles  the  so-called  purpurine,  and  leaves  indigo-blue 
undissolved,  which  may  be  recognized  by  its  evolving 
violet  vapors,  condensable  to  coppery  scales,  on  heating, 
and  by  its  dissolving,  with  a  blue  color,  in  concentrated 
sulphuric  acid.f 

The  odor  of  urine  is  caused  by  minute  quantities  of 
certain  volatile  acids,  among  which  phenylic  or  carbolic 
add  (C12H6O2)  only  is  well  known. 

SECTION  VIII. 
Ammoniacal  Salts. 

37.  In  perfectly  fresh  urine  these  are  present  in  very 
small  quantity.     The  urate  of  ammonia  which  has  been 
already  noticed  (19),  appears  to  be  one  form  in  which  the 
uric  acid  present  in  the  urine  is  held  in  solution,  since 
the  free  acid  ^quires  for  its  solution  a  larger  proportion 
of  water  than  the  secretion  usually  contains. 

38.  The  presence  of  ammonia  in  urine  is  best  shown 
by  adding  a  little  caustic  baryta  (BaO,HO)$  to  the  resi- 

*  Samples  of  urine  in  which  no  sugar  could  be  detected  by  the 
copper-test,  when  heated  witli  sulphuric  or  hydrochloric  acid,  deposited 
brown  Hakes,  and  the  filtered  liquid  gave  decided  indications  of  snirar. 
The  brown  precipitate  had  the  same  composition  as  anthranilic  acid 
(C,4H7NO4),  which  is  a  product  of  the  decomposition  of  indigo-blue  ; 
it  dissolves  in  boiling  alcohol,  with  a  fine  purple  color. 

f  Heller  calls  the  yellow  coloring  matter  of  the  urine  uroxantliin, 
terming  the  red  substance  derived  from  it  urrhvdine,  and  the  blue 
uroglaucine'. 

t  Baryta  is  here  to  be  used  in  preference  to  potash,  since  the  latter 
would  cause  the  evolution  of  ammonia  by  its  action  upon  the  u.'v.-i. 
which,  in  presence  of  the  alkalies,  is  converted  into  carbonate  of  am- 
monia (11). 

4* 


42  HEALTHY    URINE. 

due  left  after  evaporating  the  liquid  nearly  to  dry  ness  at 
a  gentle  heat,  when  the  odor  of  ammonia  will  be  percep- 
tible, and  a  rod  moistened  with  dilute  hydrochloric  acid, 
held  over  it,  will  give  rise  to  the  characteristic  white 
fumes  of  hydrochlorate  of  ammonia.  The  proportion  of 
ammonia  contained  in  healthy  urine  appears  to  be  very 
small;  in  some  forms  of  disease,  however,  especially  in 
certain  kinds  of  fever,  the  quantity  is  found  to  increase 
considerably.  Neubauer  found,  in  the  case  of  one  person 
in  health,  about  thirteen  grains  of  ammonia  in  the  excre- 
tion of  twenty-fours  hours.  In  another  case,  about  eight 
grains. 

SECTION  IX. 
Fixed  Alkaline  Salts. 

39.  In  order  to  obtain  the  fixed  salts  present  in  the 
urine,  about  eight  ounces  should  be  evaporated  to  dryness 

in  a  porcelain  dish,  in  which 
Fig.  6.  the    residue    is    afterwards 

heated  as  long  as  any  fumes 
escape;  the  resulting  carbo- 
naceous  mass  is  powdered 
an^  introduced  in  small 
portions  into  a  porcelain 
crucible  -heated  to  a  very 

low  redness.*     In  this  way 

tbe  carbon  ^f11  be  gradu- 
a11?  burnt  °ff>  an(i a  sray  or 

white  ash  left,  consisting  of 
a  mixture  of  the  alkaline 

Evaporated  Residue  of  Healthy  Urine.        an(l  earthy  SaltSJ    the  former 

may  then  be  separated  from 

the  latter  by  dissolving  in  water,  in  which  the  earthy  salts 
are  insoluble  (43).  The  composition  of  this  ash,  however, 
will  not  exactly  represent  that  of  the  inorganic  portions  of 
the  urine,  on  account  of  the  chemical  changes  induced 
among  its  constituents  during  incineration. 

*  At  a  higher  temperature,  partial  fusion  might  take  place,  rendering 
complete  incineration  impossible  ;  some  of  the  alkaline  chlorides  might 
also  be  lost. 


FIXED    ALKALINE    SALTS.  43 

40.  The  alkaline  salts,  which  in  the  healthy  secretion 
usually  amount  to  from  ten  to  twelve  parts  in  1000,  con- 
sist of  the  sulphates  of  potash  and  soda  (KO,S03)  and 
(NaO,S03\  chloride  of  sodium  (NaCl),  chloride  of  potas- 
sium (AT/),andphosphateofsoda(2#a(9,//<9,P05+ 2440). 
The  crystalline  residue  left  after  slowly  evaporating  a  few 
drops  on  a  piece  of  glass,  usually  has  the  appearance  repre- 
sented in  Fig.  6.     The  crosslets  (a)  consist  of  chloride  of 
sodium,  and  the  more  plumose  crystals  (b)  are  probably 
phosphate  of  soda. 

41.  The  presence  of  these  several  salts  may  be  shown 
by  adding  to  the  aqueous  solution  of  the  ash  the  follow- 
ing tests: — 

(a)  Nitrate  of  Silver  (AgO,N05)  throws  down  a  whitish 
precipitate,  consisting  of  a  mixture  of  chloride  (AgCl) 
and  phosphate  (3AgO,PO5)  of   silver.      These  may  be 
separated  from  each  other  by  warming  the  precipitate 
with  a  little  nitric  acid,  when  the  phosphate  will  dissolve, 
leaving  the  insoluble  CHLORIDE,  which  may  then  be  tested 
with  ammonia,  in  which  it  is  readily  soluble. 

(b)  The  acid  solution  separated  from  the  chloride  (a) 
must  now  be  cautiously  neutralized  with  ammonia,  which 
will  throw  down  a  pale  yellow  precipitate  of  PHOSPHATE 
(3AgO,P03),  which  may  be  again 'dissolved  by  adding  a 
slight  excess  of  nitric  acid. 

(c)  Chloride  of  barium  (BaCT),  or  nitrate  of  baryta  (Ba  0, 
N05\  throws  down  a  white  precipitate  of  sulphate  of 
baryta  (BaO,S03),  mixed  with  phosphate  of  baryta  (2BaO, 
IIO,P05) ;  which  latter  may  be  separated  by  dilute  hy- 
drochloric acid,  which  leaves  the  sulphate  undissolved, 
jyoving  the  presence  of  SULPHURIC  ACID.     If  the  acid 
solution  of  the  phosphate  be  neutralized  with  ammonia, 
the  phosphate  of  baryta  is  again  precipitated. 

In  order  conclusively  to  prove  the  presence  of  phos- 
phoric acid,  another  portion  of  the  aqueous  solution  of 
the  ash  should  be  acidified  slightly  with  acetic  acid,  and 
a  drop  of  perchloride  of  iron  (Fe2Cl3)  added,  which  will 
cause  a  vellowish-white  precipitate  of  perphosphate  of 
iron  (Fe203,P05). 

(d)  The  absence  of  all  bases  except  the  alkalies,  may 
be  proved  by  testing  the  solution  with  hydrosulphate  of 


44  HEALTHY    URINE. 

ammonia,  (NIT^ffS)  and  carbonate  of  soda  (Na 
neither  of  which  will  be  found  to  cause  any  precipitate. 

(e)  POTASH  may  be  shown  to  be  present  by  adding  to 
a  little  of  the  strong  solution  about  an  equal  quantity  of 
bichloride  of  platinum  (PtCl^),  which  will  cause  a  yellow 
precipitate  of  the  double  chloride  of  platinum  and  potas- 
sium (KCl,PtCl2);  and  another  portion  may  be  stirred  on 
a  slip  of  glass  with  solution  of  tartaric  acid,  which  will 
throw  down  a  white  crystalline  precipitate  of  the  bitar- 
trate  (KO,HO,08H4010). 

(/)  SODA  may  be  identified  by  dipping  a  clean  plati- 
num wire  into  the  solution,  and  heating  it  in  the  blow- 
pipe flame,  which  will  be  tinged  golden  yellow. 

42.  It  is  difficult  to  say  in  what  exact  state  of  combi- 
nation these  several  bases  and  acids  exist  in  the  urine  ; 
but  it  is  most  probable  that  each  base  is  divided  among 
the  several  acids,  and  that  a  portion  of  each  of  the  acids 
is  combined  with  some  of  each  of  the  fixed  bases,  and 
also  of  the  ammonia  (37,  40). 

SECTION  X. 
Earthy  Salts. 

43.  The  earthy  salts,  which  form  the  insoluble  portion 
of  the  ash,  and  which  usually  amount  in  healthy  urine  to 

.about  one  part  in  1000,  consist  of  the  phosphates  of  lime 
and  magnesia,  together  with  a  small  trace  of  alumina  and 
silica.      These  earthy  phosphates, 
Fig.  7.  which  are  insoluble  in  water,  ap- 

pear to  be  retained  in  solution  in 
the  urine  by  the  small  excess  of  aci^l 
(probably  phosphoric)  usually  pre- 
sent in  the  healthy  secretion,  and 
may  be  immediately  precipitated 
from  it  by  supersaturating  with 
ammonia.  The  precipitate  thus 
formed  consists  of  a  mixture  of 

MixedPhosphates.  PHOSPHATE    OF    LIME    (3CaO,P05), 

and  the  DOUBLE  PHOSPHATE  OF  AM- 
MONIA and  MAGNESIA  (2MgO,NH4O,P05-fl2Aq),  which 
is  also  called  TRIPLE  PHOSPHATE.  If  this  precipitate  be 


EARTHY    SALTS.  45 

examined  under  tlie  microscope,  it  will  generally  be 
found  to  consist  of  minute  crystals  of  the  triple  phos- 
phate, mixed  with  amorphous  particles  of  phosphate  of 
lime  (Fig.  7).  Collect  the  precipitate  upon  a  filter,  wash 
it  several  times  with  water,  and  drop  a  little  nitrate  of 
silver  upon  it.  The  formation  of  the  bright  yellow 
phosphate  of  silver  (3AgO,POa),  will  indicate  the  pre- 
sence of  phosphoric  acid. 

44.  The  crystalline  form  of  the  triple  phosphate,  as 
well  as  its  chemical  composition,  depends  upon  the  quan- 
tity of  ammonia  present  in  the  liquid  during  its  forma- 
tion. When  the  urine  is  cautiously  neutralized  with  the 
alkali,  the  crystals  are  prismatic  (Fig.  8),  and  in  a  few 
rare  cases,  penniform*  (Fig.  9),  and  appear  to  consist  of 

Fig.  8.  Fig.  9. 


Prismatic  Crystals  of  Triple  Phosphate.  Peuniform  Crystals  of  Triple 

Phosphate. 

(MgO,NH4,0,HO,P05);  while,  if  a  decided  excess  of  am- 
monia be  added,  the  crystals  are  star-like  and  foliaceous, 
as  shown  in  Fig.  10,  and  then  consist  of  (2MgO,NH4O, 
P04  +  12Aq).  When  the  urine  gradually  becomes  alka- 
line, owing  to  the  spontaneous  formation  of  ammonia 
from  the  urea  (11),  the  triple  phosphate  is  precipitated 
in  the  prismatic  form,  crystals  of  which  are  always  to  be 
detected  in  stale  urine. 

45.  Both  varieties  of  triple  phosphate  will  be  found 
to  develop  beautiful  colors  when  examined  with  polarized 
light. 

*  According  to  Dr.  H&saall,  these  consist  of  phosphate  of  lime. 


46  HEALTHY    URINE. 

Fig.  10. 


Stellate  Crystals  of  Triple  Phosphate. 

46.  The  presence  of  phosphoric  acid,  in  combination 
with  lime  and  magnesia,  together  with  a  trace  of  silica, 
in  the  insoluble  portion  of  the  ash,  may  be  shown  by 
digesting1  a  considerable  quantity  of  the  latter  in  dilute 
hydrochloric  acid,  and  filtering  the  solution  from  the  in- 
soluble residue.     This  insoluble  portion,*  the  amount  of 
which  is  usually  very  small,  may  then  be  washed,  and 
tested  for  SILICA,  by  fusion    before  the  blowpipe  with 
carbonate  of  soda,  with  which  it  will  form,  when  pure, 
a  clear  colorless  bead  (Prac.  Chem.  138.) 

47.  The  acid  solution  of  the  phosphates,  filtered  from 
the  silica,  may  then  be  divided  into  two  portions,  and 
tested  as  follows  : — 

(a)  Add  ammonia  in  slight  excess,  redissolve  the  pre- 
cipitate by  adding  acetic  acid,  and  add  a  few  drops  of 
perchloride  of  iron ;  the  yellowish-white  precipitate  (Fea 
O3,P05)  indicates  the  PHOSPHORIC  ACID. 

(b)  To  the  same  portion  add  about  twice  its  volume  of 
water,  and  boil  for  a  few  seconds  to  precipitate  the  whole 
of  the  phosphate  of  iron ;  filter,  and  add  oxalate  of  am- 
monia, which  will  precipitate  the  LIME  as  oxalate  (CaO, 
C203)- 

(c)  The  mixture  (b)  is  boiled,  and  filtered  from  the 
oxalate  of  lime ;  after  which  the  clear  solution  is  well 
stirred  with  a  decided  excess  of  ammonia,  which  will  in 
a  short  time  cause  a  deposition  of  the  crystalline  double 
phosphate  of  ammonia  and  MAGNESIA,  thus  proving  the 
presence  of  the  latter  base. 

*  This  residue  generally  contains  carbon,  which  should  be  burnt 
off  upon  platinum  foil. 


EARTHY    SALTS.  47 

48.  The  same  experiments  (cr,  I,  &  c)  may  also  be  made 
upon  the  phosphates  which  are  thrown  down  by  the  ad- 
dition of  ammonia  to  fresh  urine. 

49.  The  earthy  phosphates  may  also  be  distinguished 
by  the  following  peculiarities,  which  may  be  r^dily  seen 
either  with  or  without  the  assistance  of  the  microscope:  — 

(a)  "When  present  in  excess,  they  may  frequently  be 
precipitated  from  the  urine  in  an  amorphous  form  by 
boiling,  thus  behaving  like  albumen  (139).  The  phos- 
phatic  deposit  may  be  readily  distinguished  from  the 
latter,  by  being  soluble  in  a  few  drops  of  nitric  acid,  and 
in  not  being  reprecipitated  by  any  excess  of  that  reagent 
(140), 

(I)  The  earthy  phosphates  are  readily  soluble,  without 
effervescence,  in  dilute  acids,  such  as  the  hydrochloric, 
nitric,  and  acetic;  and  are  reprecipitated  by  neutralizing 
the  acid  solution  with  ammonia  ;  that  of  lime  being  amor- 
phous, and  the  triple  phosphate,  in  crystalline  form, 
either  prismatic  or  stellate  (43). 

(c)  They  are  insoluble  in  a  solution  of  potash.  The 
triple  phosphate,  when  warmed  with  an  excess  of  the 
alkali,  gives  off  ammoniacal  fumes,  which  may  be  detected 
by  the  smell,  and  by  the  white  cloud  formed  when  a  rod 
moistened  with  dilute  hydrochloric  ackl  is  held  at  the 
mouth  of  the  tube.  2MgO,NH40,PO5+2(7f6>,//0)= 


(d)  When  heated  before  the  blowpipe,  phosphate  of 
lime  experiences  little  or  no  change,  unless  the  heat  be 
very  intense,  and  continued  for  a  long  time,  when  it 
sometimes  partially  fuses.  The  triple  phosphate,  when 
heated,  gives  off  ammonia  and  water;  and  the  residual 
phosphate  of  magnesia  (2MgO,PO,;)  fuses  considerably 
more  readily  than  the  phosphate  of  lime.  When  the  two 
phosphates  are  mixed  in  about  equal  proportion,  they 
resemble  in  composition  the  fusible  calculus,  and  fuse 
with  extreme  facility  before  the  blowpipe  (392). 


48  QUANTITATIVE    ANALYSIS    OF 


CHAPTER    II. 

QUANTITATIVE  ANALYSIS  OF  HEALTHY  URINE. 

50.  COUNTERPOISE  or  weigh  two  Berlin  porcelain  eva- 
porating basins,  which,  for  the  sake  of  distinction,  may 
be  marked  A  and  B,  each  capable  of  holding  about  four 
ounces  of  water ;  and  retain  the  counterpoises,  marking 
them,  in  order  to  avoid  confusion.   Then  weigh  into  each 
of  the  basins,  1000  grains  of  urine,  and  allow  them  to 
evaporate  first  on  the  water-bath,  and  afterwards  in  a  hot- 
water  oven,  or  chloride  of  calcium  bath,*  until  they  cease 
to  lose  weight  when  weighed  at  intervals  of  an  hour  or 
two.    While  the  evaporation  is  going  on,  the  experiments 
described  in  paragraphs  59,  66,  &c.,  may  be  proceeded 
with.   The  specific  gravity  also  may  be  determined  (278), 
and  the  action  of  the  urine  on  test-paper  ascertained  (277). 
Then  accurately«weigh  them,  and  if  the  weights  of  both 
residues  agree  with  each  other,  the  loss  experienced  dur- 
ing evaporation  will  represent  the  quantity  of  WATER  con- 
tained in  the  urine.     If  the  weights  do  not  agree,  it  is 
probable   that  desiccation   of  at  least  one  of  the  por- 
tions has  been  incomplete ;  in  which  case  it  is  better  to 
continue  the  heat  a  short  time  longer,  until  the  results 
agree  more  closely. 

51.  The  residue  A  may  be  first  examined,  retaining  B 
for  subsequent  examination  (62). 

52.  Warm  the  residue  A  with  half  an   ounce  or  an 
ounce  of  alcohol  of  specific  gravity  about  .833,  stirring 
the  mixture  occasionally  with  a  glass  rod.     Pour  off  the 
solution  into  another  basin,  and  again  warm  the  residue 
with  a  little  more  alcohol,  fresh  portions  of  which  must 
be   added   until   it   ceases   to   dissolve  anything  more. 

*  Pract.  Chem.,  pp.  201,  212. 


HEALTHY    URINE.  49 

Whether  this  is  the  case,  may  be  known  by  evaporating 
a  drop  of  the  clear  liquid  on  platinum  foil  or  a  slip  of 
glass,  when,  if  anything  has  been  dissolved,  it  will  be  left 
behind  as  a  residue.  The  alcoholic  solution,  which  will 
contain  the  whole  of  the  urea,  contaminated  with  extrac- 
tive matter  and  other  impurities,  is  now  to  be  evaporated 
to  dryness  on  a  water-bath,  retaining  the  residue  which 
proved  insoluble  in  the  alcohol  for  subsequent  examina- 
tion (57). 

53.  The  residue,  containing  the  urea,  left  after  evapo- 
rating the  alcoholic  solution  (52),  is  now  to  be  dissolved  in 
as  small  a  quantity  as  possible  of  lukewarm  water,  and 
mixed  with  pounded  oxalic  acid  (HO,C203  +  2Aq),  which 
may  be  added  as  long  as  the  liquid,  heated  to  about  190° 
or  200°,  continues  to  dissolve  it  (14).     The  urea  is  thus 
converted  into  the  oxalate  (CyH4N20#HO,C203),  which, 
as  the  solution  cools,  crystallizes  out,  mixed  with  some 
of  the  excess  of  oxalic  acid  employed,  together  with  ex- 
tractive matters  and  other  impurities,  which  give  the 
crystals  a  more  or  less  intense  brown  color.   The  crystals 
are  to  be  washed  in  the  basin  with  a  very  small  quantity 
of  cold  distilled  water,  which  may  be  poured  off,  and 
fresh  water  added  to  the  crystals  as  long  as  it  continues 
to  become  decidedly  colored ;  by  which  means  most  of 
the  soluble  salts  and  other  foreign  matters  are  removed. 

54.  The  washings  are  now  to  be  concentrated  to  a  small 
bulk  by  evaporation  on  a  water-bath,  and  left  to  cool, 
when  a  fresh  crop  of  crystals  will  gradually  separate. 
Care  must  be  taken  that  an  excess  of  oxalic  acid  is  pre- 
sent in  the  liquid  separated  from  the  crystals,  which  may 
be  known  by  its  reddening  litmus  paper;  if  this  is  found 
on  trial  not  to  be  the  case,  a  little  more  of  the  pounded 
oxalic  acid  must  be  added  to  the  solution,  as  otherwise, 
some   of  the   urea,  which,  when   uncombined,  is   very 
soluble  in  water,  might  escape  separation. 

55.  When  the  whole  of  the  oxalate  of  urea  has  been 
separated  by  successive  crystallization  from  the  liquid, 
it    must  be  gently  pressed    between  folds  of   filtering 
paper,  and  dissolved  in  warm  water;  after  which  the 
solution  is  to  be  digested  for  a  few  hours,  at  a  tempera- 
ture of  about  100°,  with  pounded  carbonate  of  lime, 

5 


50  QUANTITATIVE    ANALYSIS    OF 

stirring  the  mixture  from  time  to  time  with  a  glass  rod, 
as  long  as  any  effervescence  is  produced.  The  oxalate  is 
thus  decomposed  in  the  following  manner:  — 

Oxalate  of  urea.  Oxalate  of  lime. 

,HO,C20Z  -f  CaO,C02  =  CaO,C203  +  CO2  +HO 

Urea. 


56.  The  urea,  which  being  soluble  remains  in  solution, 
is  to  be  separated  by  filtration  from  the  insoluble  oxalate 
and  carbonate  of  lime,  and  carefully  evaporated  to  dry- 
ness  either  on  a  water-bath  or  in  vacuo  over  sulphuric 
acid.     Its  weight  will  then  represent  the  proportion  of 
UREA  in  1000  grains  of  the  specimen  of  urine  under 
examination.* 

57.  The  portion  of  the  residue  which  proved  insoluble 
in  the  alcohol  (52),  containing  the  uric  acid,  vesical  mu- 
cus, the  extractive  matter  soluble  in  water,  but  insoluble 
in  alcohol,  the  earthy  salts,  and  most  of  the  other  saline 
matter,  is  now  to  be  well  stirred  with  successive  small 
portions  of  warm  water,  which  leaves  undissolved  the 
uric  acid,  mucus,  and  earthy  salts.     The  insoluble  matter 
is  to  be  collected  upon  a  filter,  which  has  previously  been 
dried  and  weighed,  and  then  carefully  dried  on  a  water- 
bath,  or  in  a  hot-water  oven,  and  weighed.     The  weight 
having  been  noted,  the  dry  residue  is  to  be  ignited  toge- 
ther with  the  filter  in  a  crucible,  until  the  incombustible 
ash  becomes  white,  or  very  nearly  so;  when  the  crucible 
with  its  contents  is  to  be  again  weighed.     The  difference 
between  this  weight  and  that  of  the  dry  residue  previous 
to  ignition,  gives  the  amount  of  combustible  matter,  con- 
sisting of  UKIC  ACID  and  VESICAL  MUCUS  ;  while  that  of 
the  ash  represents  the  EARTHY  PHOSPHATES  AND  SILICA. 

58.  The  portion  of  urine  A  will  now  have  given  us  the 
weight  of—  1.  The  water  ;   2.  Urea  ;   3.  Uric  acid  and 
vesical  mucus;  and  4.  Earthy  phosphates  and  silica. 

59.  For  the  purpose   of  ascertaining  the  respective 
weights  of  the  uric  acid  and  vesical  mucus,  2000  grains 

*  The  exact  determination  of  the  amount  of  urea  in  urine  must  be 
effected  by  an  indirect  method,  which  will  be  subsequently  described. 


HEALTHY    URINE.  61 

of  the  fresh  urine  may  be  concentrated  by  evaporation 
to  about  half  its  bulk,  and  mixed  with  twenty  or  thirty 
drops  of  hydrochloric  acid.*  In  the  course  of  twenty- 
four  hours,  the  whole  of  the  uric  acid  will  have  been  set 
free  by  the  hydrochloric  acid,  and  being  insoluble  (22), 
will  be  deposited  in  the  form  of  minute  crystals  on  the 
sides  and  bottom  of  the  glass.  These  are  to  be  collected 
on  a  weighed  filter,  and,  after  being  washed  with  a  little 
alcohol,  dried  in  a  hot  water  oven  or  on  a  water-bath. 
The  weight  of  this  acid,  divided  by  two  (since  it  is  derived 
from  2000  grains  of  urine),  will  represent  the  URIC  ACID 
contained  in  1000  grains  of  the  secretion  ;  and  having 
already  determined  the  quantity  of  uric  acid  and  VESICAL 
MUCUS  together  (57),  the  weight  of  the  latter  is  known 
by  deducting  from  the  combined  weights  that  of  the  uric 
acid. 

60.  The  proportion  of  uric  acid  and  mucus  may  also  be 
determined  by  evaporating  to  dry  ness  1000  grains  of  the 
urine,  previously  filtered  from  the  mucus,  and  washing 
the  residue  first  with  dilute  hydrochloric  acid  (containing 
one  part  of  acid  to  eight  or  ten  of  water),  and  afterwards 
with  a  little  alcohol.     We  thus  dissolve  out  everything 
but  the  uric  acid,  which,  after  being  washed  with  cold 
water,  may  be  dried  and  weighed. 

61.  If  it  is  required  to  determine  the  respective  pro- 
portions of  earthy  phosphates  and  silica  in  the  residue  of 
earthy  salts  (57) — which,  however,  is  seldom  necessary, 
since  the  quantity  of  silica  is  always  very  small — it  may 
be  done  in  the  following  manner :  Moisten  the  residue 
with  hydrochloric  acid,  and  evaporate  to  dryness ;   then 
digest  it  with  the  aid  of  a  gentle  heat,  in  dilute  hydro- 
chloric acid,  which  will  dissolve  out  the  phosphates,  leav- 
ing, the  SILICA  perfectly  insoluble.     The  weight  of  the 
latter  is  then  ascertained,  and  deducted  from  the  gross 
weight  of  the  earthy  salts  (57),  when  the  difference  will 
represent  that  of  the  EARTHY  PHOSPHATES  ;  or  the  phos- 
phates may  be  precipitated  from  the  hydrochloric  acid 

*  In  general,  the  uric  acid  may  be  determined  in  the  urine  without 
previous  concentration,  if  it  be  acidulated  and  set  aside  for  twenty- 
four  hours. 


52  HEALTHY    URINE. 

solution  by  supersaturating  it  with  ammonia,  filtered, 
ignited,  and  weighed. 

62.  We  have  now  to  operate  upon  the  residue  left  after 
the  evaporation  of  the  second  portion  of  urine  marked  B 
(50),  for  the  purpose  of  determining  the  weight  of — 1. 
The  animal  extractive  and  arnmoniacal  salts  ;  and  2.  The 
fixed  alkaline  salts. 

63.  The  dry  residue,  after  being  accurately  weighed,  is 
to  be  incinerated  (39)  in  a  platinum  or  porcelain  crucible, 
until  the  whole  of  the  blackness  (carbon)  has  disappeared, 
after  which  the  weight  of  the  ash  is  to  be  noted.*     The 
loss  experienced  during  ignition  being  due  to  the  com- 
bustion of  the  organic  matters  and  the  volatilization  of 
the  arnmoniacal  salts  ;  and  as  we  have  already  ascertained 
the  weight  of  the  urea,  uric  acid,  and  vesical  mucus,  we 
have  only  to  deduct  from  the  whole  amount  of  loss  the 
combined  weights  of  those  three  substances,  in  order  to 
determine  the  quantity  of  the  ANIMAL  EXTRACTIVE  AND 

AMMONIACAL  SALTS. 

64.  The  ash  obtained  by  ignition  contains  the  whole  of 
the  inorganic  matter,  or,  in  other  words,  the  fixed  alkaline 
and  earthy  salts  contained  in  the  urine.     By  deducting 
from  this  the  weight  of  the  earthy  salts  already  deter- 
mined (57),  we  obtain  the  proportion  of  FIXED  ALKALINE 
SALTS. 

65.  We  shall  thus  have  determined  the  proportion  of 
the 

Water, 

Urea, 

Uric  acid, 

Vesical  mucus, 

Animal  extractive  and  ammoniacal  salts. 

Fixed  alkaline  salts, 

Earthy  phosphates, 

Silica, 

which,  when  added  together,  ought  to  make  up  a  fraction 
less  than  1000  grains,  some  slight  loss  being  unavoidable 
during  the  course  of  the  analysis. 

*  If  an  exact  determination  of  the  amount  of  ash  be  required,  the 
dry  residue  must  be  carbonized  by  a  low  heat,  until  no  more  fumes 
are  evolved,  the  soluble  salts  thoroughly  extracted  from  it  by  boiling 
water,  and  their  weight  determined  by  evaporating  the  filtered  liquid. 
The  coal  containing  the  insoluble  salts  is  then  dried  and  burnt,  at  a 
higher  temperature,  to  a  white  ash. 


INORGANIC    SALTS.  53 

Quantitative  determination  of  Ammonia. 

65a.  Place  about  an  ounce  of  filtered  urine  in  a  shallow 
flat  evaporating  dish,  upon  which  is  supported,  by  means 
of  a  triangle  made  of  bent  glass  roc},  a  smaller  flat  dish 
containing  half  an  ounce  of  dilute  sulphuric  acid,  which 
is  known  to  be  exactly  neutralized  by  a  certain  amount 
of  a  standard  solution  of  soda.  Add  to  the  urine  about 
half  its  volume  of  milk  of  lime,  cover  the  whole  with  a 
bell-glass,  and  allow  it  to  stand  for  forty-eight  hours.  The 
ammonia  which  is  set  free  by  the  lime  will  be  absorbed 
by  the  sulphuric  acid,  and  it  only  remains  to  ascertain 
how  much  of  the  latter  has  been  neutralized  by  the  am- 
monia, which  is  easily  done  by  means  of  the  solution  of 
soda  above  referred  to.  Every  forty  grains  of  sulphuric 
acid  (SO3)  neutralized,  will  represent  seventeen  grains  of 
ammonia  (NH3).*  Dark-colored  urine,  which  easily  putre- 
fies, must  be  precipitated  with  a  mixture  of  acetate  and 
tribasic  acetate  of  lead,  and  filtered  before  determining 
the  ammonia. 

Quantitative  determination  of  the  Inorganic  Salts. 

66.  For  the  sake  of  practice  in  analysis,  it  will  be  well 
for  the  student  to  determine  the  proportions  of  the  several 
bases  and  acids  contained  in  the  ash  obtained  in  (39)  and 
(63),  but  for  purposes  of  diagnosis,  it  is  more  convenient 
to  estimate  the  alkaline  and  earthy  phosphates,  the  sul- 
phuric acid,  and  the  chlorine  in  the  original  urine,  and 
this  is  the  more  necessary  because  the  composition  of  the 
ash  of  any  given  sample  of  urine  is  liable  to  variation, 
according  to  the  temperature  at  which  the  incineration 
was  conducted. 

67.  For  the  quantitative  analysis  of  the  ash,  about  sixty 
grains  will  be  required,  which   would  be  furnished  by 
about  5000  grains  (ten  fluidouncep)  of  urine  treated  ac- 
cording to  the  directions  given  in  (39);    the  ash  should 
be  thoroughly  mixed  together  in  a  dry  mortar  whilst  still 
warm,  and  transferred  to  a  stoppered  bottle. 

68.  Determination  of  lime,  magnesia,  and  phosphoric  acid. 

*  This  process  was  devised  by  Neubauer. 


54  QUANTITATIVE    DETERMINATION 

— Heat  twenty  grains  of  the  ash  with  dilute  hydrochloric 
acid  for  a  few  minutes,  and  filter  the  solution  from  the 
undissolved  residue  (carbon  and  silica,)  taking  care  to 
wash  the  latter  as  long  as  the  washings  are  acid.  Mix 
the  filtered  solution  with  ammonia  in  excess,  stir  it  well, 
and  allow  it  to  stand  for  some  time  (if  possible  for  twelve 
hours).  Collect  the  precipitate  of  phosphate  of  lime 
(3CaO,PO5),  and  phosphate  of  magnesia  and  ammonia 
(2MgO,NH40,P05)  upon  a  filter,  wash  it  with  ammoni- 
acal  water  as  long  as  the  washings  leave  any  considerable 
residue,  when  evaporated  upon  a  slip  of  glass  and  save 
the  filtrate  and  washings  for  further  examination  (72). 

69.  Determination  of  lime. — Dissolve  the  precipitate  oft* 
the  filter  with  a  little  warm  acetic  acid,  taking  care  to 
wash  the  filter,  and  mix  the  solution  with  oxalate  of 
ammonia.  Allow  it  to  stand  for  some  time,  that  the 
oxalate  of  lime  (CaO,C2O3)  may  separate,  collect  it  upon 
a  filter,  wash  it  till  the  washings  leave  no  residue  on 
evaporation,  dry,  and  ignite,  together  with  the  filter,  in  a 
weighed  crucible,  when  the  oxalate  will  be  converted  into 
carbonate  of  lime  (CaO,CO2).  Moisten  the  ignited  pre- 
cipitate with  a  little  carbonate  of  ammonia,  to  convert 
any  caustic  lime  into  carbonate,  dry  at  a  moderate  heat, 
and  weigh.  The  amount  of  lime  may  then  be  calculated 
by  the  proportion — 

Ate.  wt.  of  carb.        Ate.  wt.  of  Wt.  of  carb.  of  lime  Wt.  of  lime  in 

lime.  lime.  obtained.  20  grs.  of  ash. 


50  :  28  ::  a  :  x 

70.  Determination  of  magnesia. — The  filtrate  and  wash- 
ings from  the  precipitate  of  oxalate  of  lime  (69),  are  con- 
centrated by  evaporation,  mixed  with  excess  of  ammonia, 
well  stirred,  and  set  aside  for  twelve  hours ;  the  precipi- 
tate of  phosphate  of  magnesia  and  ammonia  is  collected 
upon  a  filter,  washed  with  ammoniacal  water,  dried, 
ignited  and  weighed.  Since  it  is  converted  by  ignition 
into  pyrophosphate  of  magnesia  (2MgO,P05),  the  amount 
of  magnesia  will  be  calculated  by  the  proportion — 

Ate.  wt.  of            Ate.  wt.  of  Wt.  2MgO,PO,  Wt.  of  magnesia  in 
2MgO,P04.                 2MgO.                    obtained.  20  grs.  of  ash. 
, >       ^- , 

111-4         :         40-4 


OF    THE    INORGANIC    SALTS.  55 

By  deducting  the  weight  of  the  magnesia  from  the  total 
weight  of  the  precipitate,  we  obtain  the  amount  of  phos- 
phoric acid  which  was  in  combination  with  magnesia  in 
the  twenty  grains  of  ash  employed. 

71.  Determination  of  phonphnric  acid. — In  order  to  de- 
termine the  phosphoric  acid  which  was  in  combination 
with  the  lime,  the  filtrate  and  washings  from  the  phos- 
phate of  magnesia  and  ammonia  (70)  may  be  concen- 
trated by  evaporation,  and  the  phosphoric  acid  precipi- 
tated by  adding  a  mixture  of  sulphate  of  magnesia,  chlo- 
ride of  ammonium,  and  ammonia,  and  proceeding  with 
the  precipitate  as  in  the  last  experiment,  the  amount  of 
phosphoric  acid  being  calculated  by  the  proportion — 

Ate.  wt.  of  Act.  vrt,  of       Wt.  of  2MgO,POk      \Vt.  of  phosphoric  acid 

•    2MgO.POs.  POS.  obtained.  in  20  grs.  of  ash. 


111-4         :          71         ::  a  :  x 

72.  To  ascertain  the  amount  of  the  phosphoric  acid 
which  was  in  combination  with  the  alkalies,  the  filtrate 
and  washings   from  the   first   precipitate   produced  by 
ammonia  (68)  are  evaporated  to  a  small  bulk,  and  the 
phosphoric  acid  determined  precisely  as  in  the  last  case. 

73.  Determination    of   the    chlorine. — Dissolve    twenty 
grains  of  the  ash  in  a  little  dilute  nitric  acid  with  the 
aid  of  heat,  filter,  wash  the  filter  till  the  washings  are  no 
longer  acid,  and  mix  the  filtered  solution  with  nitrate  of 
silver  as  long  as  it>  causes  a  fresh  precipitate;  stir  the 
solution  briskly  to  favor  the  separation  of  the  chloride 
of  silver,  collect  the  precipitate  upon  a  small  filter,  wash 
it   till  the  washings   are  no  longer  rendered   turbid  by 
hydrochloric  acid,  dry  it,  detach  every  particle  from  the 
filter,  and  fuse  it  carefully  in* a  weighed  porcelain  cru- 
cible; burn  the  filter,  allowing  the  ash  to  drop  into  the 
crucible,  again   ignite  till  all  the  carbon   has  burnt  off', 
and  weigh.*     From  the  weight  of  the  chloride  of  silver 
that  of  the  chlorine  is  calculated  by  the  proportion — 

*  If  the  precipitate  be  too  small  to  be  detached  from  the  filter,  the 
latter  must  be  burnt  with  it,  and  the  ash  afterwards  moistened  with 
a  fnw  drops  of  nitric  and  hydrochloric  acid,  to  convert  the  reduced 
silver  into  chloride;  it  is  then  again  ignited  and  weighed. 


56  QUANTITATIVE    DETERMINATION 

Ate.  wt.  of  chloride  Ate.  wt.  of       Wt.  of  AgCl        Wt.  of  chlorine  in 

of  silver.  chlorine.-  obtained.  20  grs.  of  ash. 

143-5  :       ~35r5       :  :    ~~a  :  ~x 

74.  Determination  of  sulphuric  acid  and  the  alkalies. — 
Dissolve  twenty  grains  of  the  ash  in  hydrochloric  acid, 
filter  the  solution  (68)  and  precipitate  with  excess   of 
chloride  of  barium  ;  collect  the  sulphate  of  baryta  (BaO, 
S03)  upon  a  (Swedish)  filter,  wash  it  with  hot  water  till 
the  washings  leave  no  considerable  residue  when  evapo- 
rated, and  save  the  filtrate  and  washings   for  further 
examination  (75).     Dry  the  sulphate  of  baryta,  empty 
as  much  of  it  as  possible  into  a  weighed  crucible,  burn 
the  filter  so  that  the  ash  may  fall  into  the  crucible,  ignite 
till  all  the  carbon  has  burnt  off,  and  weigh.    The  amount 
of  sulphuric  acid  is  calculated  by  the  proportion — 

Ate.  wt.  of  Wt.  of  BaO.SO,         Wt.  of  sulphuric  acid 

S03.  obtained.  in  20  grg.  of  ash. 

116-5    .    :         40         :  :         ~T  :  T 

75.  In  the  liquid  filtered  from  the  sulphate  of  baryta, 
the  potash  and  soda  have  now  to  be  determined.     For 
this  purpose,  ammonia  in  excess,  and  carbonate  of  ammo- 
nia must  be  added,  and  the  solution  gently  heated.     The 
excess  of  baryta,  together  with  the  lime,  magnesia,  and 
phosphoric  acid,  are  thus  precipitated,  and  must  be  fil- 
tered off,  and  washed  till  the  washings  leave  no  consider- 
able residue  on  evaporation.     The  filtrate  and  washings 
are  then  evaporated  to  a  small*  bulk,  introduced  into  a 
weighed  porcelain  or  platinum  dish,  carefully  evaporated 
to  dryness,  and  heated  to  dull  redness,  as  long  as  any 
fumes  (of  chloride  of  ammonium)  escape. 

76.  The  residue  after  ignition,  consisting  merely  of 
the  chlorides  of  potassium  and  of  sodium,  is  now  to  be 
weighed.     It  is  then  dissolved  in  a  small  quantity  of 
water,  mixed  with  a  solution  of  bichloride  of  platinum, 
and  the  mixture  is  evaporated  to  dryness  on  a  water-bath. 
The  residue  is  treated  with  successive  small  portions  of 
alcohol,  which  will  dissolve  out  the  excess  of  the  bichlo- 
ride of  platinum,  together  with  the  chloride  of  sodium  ; 
leaving  undissolved  the  double  chloride  of  platinum  and 
potassium  (KCl,PtCl2).     The  latter  is  to  be  dried  in  a 


OF    TUB    INORcJAN'U     SALTS.  67 

weighed  filter,  at  a  temperature  of  212°,  and  weighed. 
From  the  weight  of  the  double  chloride  thus  obtained, 
we  may  then  calculate  that  of  the  POTASH  equivalent  to 
it,  as  follows: — 

Ate.  wt.  of  tho  douM<-  Wt.  of  potash 

chloride  of  platinum        Ate.  wt  ol         tt  t.  "t  H.e il.mi.l.'         in  „„ 
aDdi)..t:issium.  potash.  chloride  obtained. 


244-1  :  47         :  :  a  :  x 

77.  From  the  weight  of  potash  thus  obtained,  we  are 
enabled  to  ascertain  how  much  of  the  mixed  chlorides 
(76)  was  chloride  of  potassium;  and  the  difference  be- 
tween the  latter  and  the  gross  weight  will  of  course  repre- 
sent the  quantity  of  chloride  of  sodium.     The  weight  of 
chloride  of  potassium  equivalent  to  the  potash  is  for  this 
purpose  calculated  as  follows: — 

Ate.  wt.  of          Ate.  wt.  of  chlo-         Wt.  of  pot-        Wt.  of  chloride  of  potassium  con- 
potash,  ride  of  potassium,      ash  obtained.         tained  in  the  mixed  chlorides. 

47          :  74-5          :  :    T~        :  ~T 

78.  The  weight  of  chloride  of  potassium  thus  calculated 
is  then  deducted  from  the  weight  of  the  mixed  chlorides 
(76),  and  the  difference  will  represent  the  weight  of  chlo- 
ride of  sodium  ;  thus: — 

Weight  of  mixed  chlorides       .... 
Deduct  weight  of  chloride  of  potassium    . 
Weight  of  chloride  of  sodium    .... 

79.  The  whole  of  the  soda,  however,  does  not  exist  in 
the  urine  as  chloride  of  sodium,  a  portion  of  it  being  in 
combination  with   phosphoric,   and,   perhaps,   also  with 
some  of  the  other  acids  present.     We  have,  therefore,  to 
calculate  from  the  quantity  of  chlorine  obtained  in  a  for- 
mer experiment  (73)  how  much  of  the,  chloride  of  sodium 
obtained   in   paragraph  78  existed  as  such  in  the  urine. 
This  is  done  as  follows: — 

Ate.  wt.  of         Ate.  wt.  of  chlo-          Wt.  of  chlorine  in         Wt.  of  chloride  of  sodium 
chlorino.  rido  of  sodium.  20  grs.  of  ash.  in  -JO  grs.  of  ash. 


35-5         :  58-5  :  :  a  :  x 

80.  The  quantity  of  CHLORIDE  OF  SODIUM  thus  calculated 
is  deducted  from  the  whole  weight  of  chloride  of  sodium 
previously  obtained  (78),  and  the  difference  will  represent 
the  amount  of  chloride  of  sodium  equivalent  to  the  SODA, 


58  QUANTITATIVE    DETERMINATION 

winch  in  the  urine  was  combined  with  phosphoric  or 
other  acids ;  thus: — 

Difference  between 

Ate  wt.  of  chlo-        Ate.  wt.        the  two  amounts  of     Soda  existing  as  such 
ride  of  sodium.          of  soda.        chloride  of  sodium.       in  20  grs.  of  the  ash. 

58-5  :       31      ::  ~a  :  ~~T~ 

81.  All  the  qualities  obtained  in  the  foregoing  experi- 
ments (68  to  80),  represent  the  amounts  of  the  several 
saline  ingredients  contained  in  twenty  grains  of  the  ash; 
as,  however,  the  organic  ingredients  were  estimated  as 
contained  in  1000  grains  of  urine  (65),  the  proportion  of 
the  inorganic  constituents  should  also  be  reduced  to  the 
same  scale.  This  may  be  done  in  the  case  of  each  con- 
stituent by  the  following  calculation: — 


Quantity  of  in- 
organic mat- 
ter in  1000 
grs.  of  urine. 


fWt.  of  each  consti- 
tuent    obtained 
from  20  grs.   of 
the  ash. 
I 


Wt.  of  that 
constituent 
contained 
in  1000  grs. 
of  urine. 


82.  Determination  of  the  alkaline  and  earthy  phosphates, 
the  sulphuric  acid,  and  the  chlorine  in  the  original  urine. — 
Although  it  would  be  very  difficult  to  determine  these 
constituents  in  the  original  urine  with  perfect  exactness, 
it  may  be  effected  with  sufficient  accuracy  for  the  purpose 
of  diagnosis,  since  the  results  of  the  analysis  of  each  spe- 
cimen of  urine  are  affected  by  the  same  sources  of  error, 
and  may  be  compared  with  safety. 

To  ascertain  the  amount  of  earthy  phosphates,  1000 
grains  of  the  urine  may  be  mixed  with  excess  of  ammo- 
nia, and  set  aside  for  some  hours.  The  precipitate  is  then 
filtered  off  and  washed,  as  in  (68),  dried,  ignited,  and 
weighed. 

The  phosphoric  acid  contained  in  the  solution  filtered 
from  this  precipitate  will,  of  course,  be  the  measure  of 
the  alkaline  phosphates  present.  In  order  to  determine 
its  amount,  the  filtrate  and  washings  are  precipitated  with 
a  mixture  of  sulphate  of  magnesia,  chloride  of  ammonium, 
and  ammonia,  set  aside  for  twelve  hours,  and  further 
treated,  as  in  (71). 

Volumetric  determination  of  phosphoric  acid  in  urine. — 
The  phosphoric  acid  in  urine  may  be  determined  very 


OF    THE    INORGANIC    SALTS.  59 

easily,  and,  after  a  little  practice,  with  considerable  exact- 
ness, by  ascertaining  the  amount  of  iron  required  to  pre- 
cipitate it  as  phosphate  of  sesquioxide  of  iron  (Fe2O3P05) 
from  the  urine,  acidified  by  acetic  acid. 

A  solution  of  sesquichloride  of  iron  of  known  strength 
is  prepared  by  dissolving  twenty-eight  grains  of  clean 
thin  iron  wire  in  half  an  ounce  of  hydrochloric  acid,  with 
the  aid  of  heat,  and  gradually  adding  one  drachm  of  nitric 
acid ;  the  solution  is  evaporated  very  nearly  to  dryness 
at  a  gentle  heat,  and  the  residue  dissolved  in  water.  If 
the  solution  is  not  clear,  it  is  rendered  so  by  adding  a 
very  little  hydrochloric  acid,  and  it  is  then  diluted  to 
2000  grains.  100  grains  of  this  solution  correspond  to 
T775  grains  of  phosphoric  acid. 

In  order  to  confirm  this,  3'58  grains  of  pure  crystal- 
lized'phosphate  of  soda  (2NaO,IIO,P05  + 24Aq)  are  dis- 
solved in  an  ounce  of  water  in  a  small  beaker,  the  solu- 
tion mixed  with  a  little  ammonia,*  then  with  an  excess 
of  acetic  acid,  and  the  solution  of  iron  added  from  a 
burette  until  a  trace  of  iron  can  be  detected  in  the  filtered 
liquid  by  ferrocyanide  of  potassium. 

The  most  convenient  mode  of  filtering  a  little  of  the 
fluid  consists  in  employing  a  small  tube  about  five  inches 
long  and  half  an  inch  wide,  open  at  both  ends,  which 
should  be  turned  over  like  the  rim  of  a  test-tube.  Over 
one  of  these  ends  a  circular  piece  of  filtering  paper  is 
tightly  bound  by  a  platinum  wire,  so  that  its  edges  may 
overlap  about  two  inches  of  the  tube.  The  filter-paper 
having  been  moistened,  it  is  dipped  about  an  inch  below 
the  surface  of  the  liquid  containing  the  precipitate,  when 
a  few  drops  of  the  clear  liquid  will  enter  the  tube,  and 
may  be  poured  into  a  test-tube  containing  a  little  dilute 
solution  of  ferrocyanide  of  potassium.  As  soon  as  it  is 
found  that,  on  making  this  experiment,  a  slight  blue 
tinge  is  produced,  it  is  known  that  a  sufficient  quantity 
of  the  iron  solution  has  been  added. 

The  3*58  grains  of  phosphate  of  soda  should  have 

*  This  ammonia  serves  to  neutralize  the  hydrochloric  acid  which 
is  set  free  in  the  reaction,  and  which  would  otherwise  dissolve  the 
phosphate  of  iron  ;  2NaO,  HO,POr,  -f  Fe2CL  =  Fe2O,,PO5  -f  2NaCl  -f 
HC1. 


60  QUANTITATIVE    DETERMINATION,  ETC. 

required  forty  grains  of  the  iron-solution  for  complete 
precipitation. 

In  order  to  determine  the  phosphoric  acid  in  urine, 
500  or  1000  grains  (according  to  the  state  of  concentra- 
tion) may  be  mixed  with  ammonia  in  excess,  then  with 
acetic  acid  in  excess,  and  afterwards  tested  with  the  iron 
solution  in  the  manner  just  described.  From  the  number 
of  grain  measures  of  this  solution  required  to  complete 
the  precipitation,  the  amount  of  phosphoric  acid  is  cal- 
culated by  the  proportion — 

Grs.  of  iron        Phosphoric 
solution.  acid. 

100         :       1*775         :  :         Grs.  of  solution  used         :         x 

If  it  be  desired  to  determine  the  amount  of  phosphoric 
acid  existing  in  combination  with  lime  and  magnesia, 
1000  grains  of  urine  may  be  mixed  with  ammonia  in 
excess,  allowed  to  stand  for  an  hour  or  two,  filtered  from 
the  precipitated  phosphates,  the  filtered  liquid  acidified 
with  acetic  acid,  and  tested,  as  before,  with  the  iron  solu- 
tion. TJae  difference  between  the  amount  of  phosphoric 
acid  thus  obtained  and  the  total  quantity  in  1000  grains, 
inferred  from  the  former  determination,  will  represent 
the  phosphoric  acid  existing  in  the  form  of  earthy  phos- 
phates. 

83.  For  the  determination  of  the  sulphuric  acid,  500 
grains  of  the  urine  are  acidified  with  hydrochloric  acid, 
precipitated  by  chloride  of  barium  and  the  precipitated 
sulphate  of  baryta  treated  as  in  (74). 

The  chlorine  may  be  determined  by  acidifying  500 
grains  of  urine  with  nitric  acid,  precipitating  with  nitrate 
of  silver,  and  proceeding  as  in  (73),  avoiding  as  far  as 
possible,  the  reducing  effect  of  light  upon  the  silver-salt 
in  the  presence  of  organic  matter. 

84.  If  it  be  required  to  compare  the  acidity  of  different 
specimens  of  urine,  it  may  be  effected  by  adding  to  1000 
grains  of  the  urine,  from  a  graduated  burette,  a  weak 
solution  of  carbonate  of  soda,  of  known  strength,  until 
it  ceases  to  redden  litmus  paper.     Of  course  the  degrees 
of  acidity  will  vary  as  the  quantities  of  carbonate  of  soda 
employed. 


COMPOSITION    OF    HEALTHY    URINE. 


61 


CHAPTER   III. 


AVERAGE   COMPOSITION   OF  HEALTHY    URINE. 

85.  THE  following  analysis  of  healthy  human  .urine 
will  serve  to  give  some  idea  of  its  average  composition. 
Although  iu  the  amount  of  the  several  constituents  they 
will  be  seen  to  differ  considerably  from  each  other,  it 
will  be  found  that  these  differences  are  not  really  quite 
so  great  as  they  at  first  sight  appear,  being  in  a  great 
measure  owing  to  variations  in  the  relative  proportions 
of  water  and  solid  ingredients  (1). 


Analysis  I.    (Berzelius.') 

Water ,    . 

Urea    ........ 

Uric  acid 

Lactic  acid,  lactate  of  ammonia,  and  extrac- 
tive matters     ...... 

Mucus          ....... 

Sulphate  of  potash       . 

Sulphate  of  soda ...... 

Phosphate  of  soda 

Biphosphate  of  ammonia     . 
Chloride  of  sodium       . 
Muriate  of  ammonia     . 
Phosphates  of  lime  and  magnesia 
Silica  . 


933-00 

30-10 

1-00 

17-14 

0-32 

3-711 

3-1(3 

2-94 

1-65 

4-45 

1-50 

1-00 

0-03  j 


1000-00 


(Simon.) 


Analysis  11 
Specific  gravity  1012. 

Water 

Urea 

Uric  acid 

Extractive  matters  and  ammoniacal  salts 
Chloride  of  sodium    .... 

Sulphate  of  potash 3-508 

Phosphate  of  soda 2-330 

Phosphates  of  lime  and  magnesia      .         *     0-664 
Silica a  trace 


956  000 
14-578 

0-710 
12-940 

7-280 


998-000 


6 


62 


COMPOSITION    OF    HEALTHY    URINE. 


Analysis  III.    (Dr.  Miller.) 

Specific  gravity  1020. 

Water      .         .         .  956-8000 

Urea        .         .         .     14-2300" 

Uric  acid          .         .       0-3700 

29.812      • 

Alcohol  extractive  .     12-5270 

Organic 

Water  extractive     .       2-5204 

matters. 

Vesical  mucus        .       0-1650, 

Chloride  of  sodium  .       7-2195  ' 

43-16 

Phosphoric  acid       .       2-1189 

Solid  matters. 

Sulphuric  acid        .       1-7020 

Lime       .         .         .       0-2101 

13-349 

Magnesia         .         .       0-1198 

Fixed  salts.  , 

Potash     .         .         .       1-9260 

Soda        .         .         .       0-0536, 

999-9623 


Analysis  IV.    (Afarchand.) 


Water    
Urea      ....... 
Uric  acid       

933-199 

32-675  ] 
1-065 
1-521 

Extractive  matters        .... 
Mucus   ....... 
Sulphate  of  potash        .... 
Phosphate  of  soda          .... 

11-151 

0-283 
3-587 
3-056 
3-213 

66-8 
Solid 
matters. 

Biphosphate  of  ammonia 
Chloride  of  sodium         .... 
Muriate  of  ammonia       .... 
Phosphates  of  lime  and  magnesia 

1-552 
4-218 
1-652 
1-210 

1-618  J 

1 

000-000 

mm 

Analysis  V.    (Lehmann 

Water    
Urea      

•MWMnOMMM 

0 

937-682 
31-4501 
1-021 

1-496 

Water  and  alcohol  extractives 
Lactates         ...... 
Chlorides  of  sodium  and  ammonia 
Alkaline  sulphates         .... 
Phosphate  of  soda          .... 
Phosphates  of  lime  and  magnesia  . 
Mucus   

10-680 
1-897 
3-646 
7-314 
3-765 
1-132 
0-112  j 

62-318 
i.      Solid 
matters. 

1000-195 


MORBID    URINE. 


Analysis  VI.    (Becquerel.) 

Showing  the  comparative  composition  of  Male  and  Female  Urine. 
Mean  composition       DUto  of  f()ur          General 


Specific  gravity 
Water    . 

Solid  constituents 
Urea  . 
Uric  acid    . 
Other  organic  matters 
Fixed  salts 

Consisting  of — 
Chlorine 

Sulphuric  acid     . 
Phosphoric  acid   . 
Potash 
Soda,  lime,  and  magnesia 


1018-9 

1015-12 

1017-01 

968-815 

975-052 

971-935 

31-185 

24-948 

28-066 

13-838 

10-366 

12-102 

0-391 

0-406 

0-398 

s        9-261 

8-033 

8-047 

7-695 

6-143 

6-919 

0-502 

0-317 
1-300 


CHAPTER  IY. 

MORBID   URINE. 

86.  THE  urine  passed  during  a  diseased  state  of  the 
system,  is  almost  invariably  more  or  less  altered  in  its 
composition,  and  frequently  presents  physical  peculiari- 
ties, as  of  color,  opacity,  &c.,  which  are  at  once  apparent 
on  the  most  cursory  examination.  The  variations  which 
are  found  to  occur  in  the  chemical  composition  of  morbid 
urine  may  be  divided  into  two  classes,  viz: — 

1st.  Those  in  which  no  abnormal  ingredient  is  present; 
but  in  which  one  or  more  of  the  normal  constituents 
is  present  either  in  greater  or  less  proportion  than 
is  found  in  healthy  urine,  or  is  altogether  absent. 

2d.  Those  in  which  one  or  more  ingredients  are  pre- 
sent, which  are  not  found  in  the  healthy  secretion. 


64  MORBID    URINE. 

I.  Urine  containing  no  abnormal  ingredient,  but  in  which  an 
excess  or  deficiency  of  one  or  more  of  its  normal  constituents  is 
present. 

SECTION  I. 
Urine  containing  Urea  in  abnormal  quantity. 

87.  Urine    containing  an   excess  of  urea,  is   chiefly 
characterized  by  its  high  specific  gravity,  in  which  respect 
it  resembles  that  secreted  by  diabetic  patients  (116).     If 
the  urea  be  present  in  large  excess,  it  deposits  irregular 
rhomboidal  crystals  of  the  nitrate  (C2H4N202,HO,NO5), 
when  the  urine,  either  in  its  natural  state,  or  especially 
when    slightly   concentrated,  is   mixed   with   an   equal 
quantity  of  nitric  acid  (181).     The  proportion  of  urea 
present  in  the  healthy  urine  passed  during  the  twenty- 
four  hours  is  usually  about  fourteen  or  fifteen  parts  in 
1000  (10);  while  in  disease  it  often  amounts  to  thirty 
parts,  or  even  more. 

SECTION  II. 
Urine  containing  Uric  (or  Lithic)  Acid  in  abnormal  quantity. 

88.  When  urine  contains  an  excess  of  uric  acid,  it  has 
usually  rather  a  higher  color  than  the  healthy  secretion, 
either  deep  amber  or  reddish  brown.    Its  specific  gravity 
is  seldom   much  higher  than  1020  or  1025,  unless  an 
excess  of  urea  is  also  present,  which  is  not  unfrequently 
the  case.     It  generally  has  a  decided  acid  reaction  to 
test-paper;  and  if  the  uric  acid  is  present  in  .any  con- 
siderable excess,  it  is  partially  deposited  as  the  urine 
cools,  in  the  form  of  a  crystalline  sediment,  usually  of  a 
more  or  less  decided  red  color,  and  frequently  mixed 
with  urate  of  ammonia,  mucus,  and  other  matters.*     The 
crystalline  forms  in  which  uric  acid  is  found  in  the  urine, 
are  represented  in  paragraph  186.     This  deposition  of 
uric  acid  is  greatly  accelerated  by  the  addition  of  a  few 
drops  of  nitric  or  hydrochloric  acid  to  the  urine  (20). 

89.  The  urine  of  infants  and  young  children  not  un- 
frequently  deposits    lozenge  shaped   crystals   of   nearly 

*  Hippuric  acid  lias  been  known  to  deposit  together  with  uric  acid. 


MORBID    URINE.  65 

pure  uric  acid,  containing  only  a  trace  of  yellow  coloring 
matter.  It  rarely  happens  that  uric  acid  is  deposited  in 
the  solid  state  previous  to  emission,  being  held  in  solu- 
tion in  the  warm  liquid,  and  gradually  separating  in  the 
form  of  a  sediment,  as  the  secretion  cools  (186). 

90.  The  quantity  of  uric  acid,  which,  in  the  healthy 
secretion,  is  seldom  more  than  from  0*3  to  1*0  in  1000 
parts,  varies  in  morbid  urine  from  a  scarcely  perceptible 
trace  to  upwards  of  two  parts  in  1000. 


SECTION  HI. 
Urine  containing  an  excess  of  Urate  (or  Lithate)  of  Ammonia. 

91.  Urine  containing  an  excess  of  urate  of  ammonia 
varies  very  much  in  color  and  appearance,  being  some- 
times pale  and   of  low  specific  gravity,  but  more  fre- 
quently   high     colored,    dense, 

and   turbid.     It    is    most    com-  Fig-  H« 

monly  slightly  acid,  but  is  also 
met  with  neutral  and  even  alka- 
line. The  urate  of  ammonia  is 
gradually  deposited  as  the  urine 
cools,  in  the  form  of  an  amor- 
phous precipitate,  which,  with  a 
high  magnifying  power,  appears 
to  consist  of  minute  rounded 
particles,  occasionally  adhering 
together,  and  forming  irregular 
linear  masses  (Fig.  11);  fre-  urate  of  Ammonia. 

quently  mixed  with  microscopic 

crystals  of  uric  acid ;  and,  occasionally,  when  the  secre- 
tion is  neutral  or  at  all  alkaline,  with  the  earthy  phos- 
phates (106). 

92.  Urate  of  ammonia  has  been  met  with,  in  a  few 
rare  cases,  in  the  form  of  globular  masses  of  a  larger  size, 
and  pierced  with  spicular  crystals,  probably  of  uric  acid 
(Fig.  12).     Like  the  other  varieties  of  urate  of  ammonia 
deposit,  it  is  usually  found  mixed  with  crystals  of  uric 
acid. 

6* 


66  MOKBID    URINE. 

93.  Urate  of  ammonia*  constitutes  one  of  the  most 
common  of  the  urinary  deposits.     The  color  of  the  sedi- 
ment is  found  to  vary  considerably,  being 

Fig.  12.  met  with  of  all  shades,  from  pale  fawn 
color  to  reddish  purple  or  pink,  the  latter 
colors  being  due  to  the  admixture  of 
purpurine,  which  is  very  frequently  found 
associated  with  the  urates  (104,  217). 
Urate  of  soda,  and  traces  of  the  urates  of 
lime  and  magnesia,  are  not  unfrequently 
urate  of  Ammonia.t  found  associated  with  urate  of  ammonia 
deposits. 

94.  A  deposit  of  urate  of  ammonia  readily  dissolves 
when  the  urine  containing  it  is  gently  warmed;  and  is 
again  precipitated  as  the  liquid  cools.     If,  however,  as  is 
often  the  case,  it  contains  also  an  admixture  of  free  uric 
acid  or  earthy  phosphates,  the  deposit  will  not  wholly 
dissolve  on  the  application  of  heat,  those  substances  being 
nearly  as  insoluble  in  hot  as  in  cold  water.     The  pre- 
sence of  purpurine  (104,  217)  usually  renders  the  urate 
less  easily  soluble  when  warmed. 

95.  When  a  deposit  of  urate  of  ammonia  is  treated 
with   a   little   dilute   hydrochloric  or  acetic   acid,  it  is 
decomposed ;  and  minute  crystals  of  uric  acid  shortly 
appear,  which  may  be  readily  distinguished  under  the 
microscope  (194). 

SECTION  IV. 
Urine  containing  Urate  (or  Lithtite)  of  Soda. 

96.  The  acid  urate  of  soda  (NaO,HO,C1?H2N4O4)  is  also 
a  frequent  sediment   in   the    urine,  particularly  in    the 
urine  of  patients  taking  medicinally  the   carbonate  or 
other  salts  of  soda.     It  may  generally  be  recognized  with- 
out difficulty  under  the  microscope,  usually  forming  mi- 

*  The  amorphous  deposit  formerly  described  and  figured  as  urate 
of  ammonia  has  been  proved  by  Dr.  Bence  Jones  to  consist  of  different 
acid  urates,  among  which,  acid  urate  of  potash,  occasionally  predomi- 
nates. On  washing  it  with  cold  water,  crystalline  uric  acid  separates, 
although  none  could  be  perceived  in  the  unwashed  deposit. 

f  See  note  to  (93). 


MORBID    URINE.  67 

nnte  globular  and  sometimes  granulated  Fig-  13. 

aggregations,  with  occasionally  irregular 
and  curved  protuberances,  as  shown  in       ° 


97.  It  resemble»the  urate  of  ammonia 
in  being  soluble  in  hot  water  (22,  192), 
and  also  in  most  of  its  chemical  charac- 
ters;   giving    the    same    purple-colored        urate  of  soda, 
residue  when  tested  with  nitric  acid  and 

ammonia  (23).  It  also  yields  crystals  of  uric  acid,  when 
treated  with  dilute  hydrochloric  acid  (194).  When 
warmed  with  potash,  however,  it  does  not  of  course  give 
off  ammoniacal  fumes  (377);  and  by  this,  and  more  espe- 
cially by  its  behavior  before  the  blowpipe  (202),  and  by 
its  microscopic  appearance,  it  may  readily  be  distin- 
guished from  the  ammoniacal  salt.  The  two  salts  are  fre- 
quently found  occurring  together  in  the  same  deposit. 

SECTION  V. 
Urine  containing  an  excess  of  Hippuric  Acid. 

98.  There  is  but  little  that  can  be  said  to  be  character- 
istic in  the  appearance  of  urine  in  which  an  excess  of 
hippuric  acid  is  present.     It  is  most  commonly  either 
neutral  or  slightly  acid  to  test  paper,  but  occasionally 
alkaline;  and  is  in  most  cases  pale  and  whey-like,  and  of 
low  specific  gravity.     The  mode  of  its  detection  will  be 
found  described  in  paragraphs  206,  &c. 

SECTION  VI. 
Urine  containing  an  excess  of  Mucus. 

99.  Mucous  urine  is  most  commonly  very  similar  in 
color  to  the  healthy  secretion.     It  deposits  a  viscid,  tena- 
cious sediment,  usually  of  a  dirty  yellowish  color,  con- 
sisting chiefly  of  mucus  mixed  with  epithelium  (328); 
which,  when  agitated,  does  not  mix  again  uniformly  with 

*  The  acid  urate  of  soda  (NaO,HO,C10H2N404  -f  2Aq)  has  been  ob- 
tained artificially  in  transparent  granules,  which  might  be  mistaken, 
under  the  microscope,  for  fat-globules,  but  when  washed  with  water 
they  assume  the  ordinary  appearance  of  urate  of  soda. 


68  MORBID    URINE. 

the  fluid,  but  coheres  together  in  tenacious,  ropy  masses, 
entangling  and  retaining  numerous  bubbles  of  air. 

100.  Urine  containing  an  excess  of  mucus  is  generally 
neutral  or  slightly  acid  when  passed,  unless  it  has  been 
retained  some  time  in  the  bladder,  wken  it  is  not  unfre- 
quently  alkaline ;  and  when  this  is  not  the  case,  it  very 
speedily  becomes  so,  owing  to  the  rapid  conversion  of 
the  urea  into  carbonate  of  ammonia  under  the  influence 
of  the  mucus  (11).     This  change  takes  place  first  in  the 
portion  of  the  fluid  which  is  in  contact  with  the  mucous 
sediment :  this  may  frequently  be  seen  in  specimens  of 
slightly  acid  urine,  the  upper  portions  of  which  redden 
litmus  paper ;  but  if  the  lower  part,  more  immediately  in 
contact  with  the  mucus,  be  tested,  it  will  be  found  to 
restore  the  original  blue  color. 

101.  Mucous  urine  differs  from  that  containing  pus,  in 
the  ropy  and  tenacious  character  of  the  deposit;  and  also 
in  not  giving  any  sensible  indication  of  albumen  when 
tested  with  heat  and  nitric  acid  (254),  unless  the  albumen 
be  derived  from  some  other  independent  source,  which  is 
sometimes  the  case  (255).     Minute   traces  of  albumen, 
indeed,  are  present  in  the  undiluted  mucous  fluid,  but 
the  quantity  is  so  small,  that,  when  mixed  with  urine,  it 
is  incapable  of  being  detected  (663). 

102.  The  mucous  deposit  is  frequently  found  mixed 
with  a  considerable   quantity  of  earthy  phosphates   or 
urates ;  in  which  case  its  opacity  renders  it  more  liable 
to  be  mistaken  for  pus.    The  true  nature  of  such  a  mixed 
deposit  is,  hov/ever,  readily  distinguished  by  microscopic 
examination,  which  should  always  be  had  recourse  to  in 
such  cases  (156,  211,  328). 

SECTION  VII. 

Urine  containing  an  excess  of  Extractive  and  Colgring 
Matters. 

103.  Urine  containing  extractive  matters  in  excess  is 
usually  more  highly  colored  than  the  natural  secretion, 
a  large  proportion  of  what  is  included  under  the  title  of 
extractive  matter,  consisting  apparently,  in  most  cases, 
of  the  peculiar  coloring  matters  of  the  urine.     When 


MORBID    URINE.  69 

boiled,  and  subsequently  mixed  with  a  little  hydrochloric 
acid,  such  urine  becomes  of  a  more  or  less  decided  red 
color  (215);  and  on  cooling,  usually  deposits  a  quantity 
of  brownish  or  bluish-black  sediment,  which  is  readily 
soluble  in  alcohol. 

104.  It  is  not  unfrequently  the  case,  that  the  peculiar 
red  coloring  matter  called  purpurine  is  present  in  con- 
siderable  quantity  in    certain  forms   of  morbid   urine. 
This,  when  a  deposit  of  urate  of  soda  or  ammonia  is  also 
present,  is  precipitated  with  the  urate,  giving  the  sedi- 
ment a  pink  or  red  color  (217).     When  no  deposit  of 
urate  exists,  the  purpurine  remains  in  solution,  giving 
the  urine  a  more  or  less  bloody  appearance,  which  may 
sometimes  lead  to  the  suspicion  that  blood  is  present. 
For  the  methods  of  identifying  purpurine,  see  paragraphs 
216  to  221. 

SECTION  VIII. 

Urine  containing  an  abnormal  proportion  of  Fixed  Alkaline 

Salts. 

105.  When  these  salts  are  present  in  excess,  they  tend 
to  raise  the  specific  gravity  of  the  secretion.     The  quan- 
tity of  soluble  saline  matter  may  be  readily  estimated 
in  the  mass,  by  incinerating  the  dry  residue  left  after 
evaporating  a  known  weight  of  the  urine,  and  treating  the 
ash  with  water,  which  will  dissolve  out  the  alkaline  salts, 
leaving  the  earthy  phosphates  and  silica  undissolved.* 
The  aqueous  solution    is   then   evaporated  to  dryness, 
ignited,  and  weighed.     The  individual  proportion  of  the 
several  salts,  which  is  sometimes  a  point  of  considerable 
interest,  may  be  determined  in  the  manner  described  in 
paragraphs  66  to  84. 

SECTION  IX. 
Urine  containing  the  Earthy  Phosphates  in  abnormal  quantity. 

106.  The  physical  characters  of  urine  containing  an 
excess  of  earthy  phosphates  vary  considerably.    The  color 
is  most  commonly  pale,  and  the  specific  gravity  rather  low, 
but  it  is  also  occasionally  dark,  and  of  high  specific  gravity, 

*  See  note  to  (63). 


70 


MORBID    URINE. 


especially  when  urea  is  present  in  large  quantity  (87, 
301).  It  is  generally  slightly  acid  when  passed,  but 
shortly  becomes  neutral  or  alkaline  (43),  when  the  phos- 
phates are  precipitated,  often  in  large  quantity,  in  the 
form  of  a  crystalline  sediment,  the  color  of  which  varies 
from  white  and  gray  to  a  yellow  or  reddish  brown. 
When  white  or  gray,  the  sediment  will  probably  be 
found  to  consist  chiefly  of  phosphates  mixed  with  mucus; 
when  yellowish  or  red,  it  will  probably  be  found  to  con- 
tain, in  addition,  a  certain  amount  of  uric  acid,  or  urate 
of  soda,  or  ammonia,  most  commonly  one  of  the  latter. 

107.  It  must  be  borne  in  mind  that  the  spontaneous 
occurrence  of  a  precipitate  of  earthy  phosphates,  is  not 
of  itself  a  proof  that  they  are  present  in  excess;  nor,  on 
the  other  hand,  is  the  non-occurrence  of  a  deposit  a  proof 
tKat  a  small  quantity  only  is  present.     When  the  urine 
is  acid,  as  in  health,  they  may  be  retained  in  solution  in 
considerable  quantity,   without  forming  any  solid  sedi- 
ment; while  if  the  secretion  is   neutral   or  alkaline,  a 
comparatively  small  amount  of  earthy  phosphates  may 
be  precipitated  in  the  form  of  a  deposit. 

108.  When  examined  with  the  microscope,  deposits  of 
the  earthy  phosphates  will  frequently  be  found  to  contain 
both  the   crystalline  triple  phosphate  (MgO,NH40,HO, 
P05),  and  also  phosphate  of  lime,  in  the  form  of  an 
amorphous  powder,  or  in  minute,  irregular,  rounded  par- 
ticles (43,  44).     Minute  dumb-bells,  like  those  of  oxalate 
of  lime  (Fig.  25),  have  also  been  met  with. 

Crystallized  phosphate  of  lime  (Fig.  14)  (2CaO,HO, 

P05)  is  by  no  means 
uncommon  in  urine. 
It  may  always  be  ob- 
tained by  partially 
neutralizing  the  fresh 
urine  with  ammonia, 
and  setting  it  aside. 

109.  The  quantity 
of  earthy  phosphates 
which  in  healthy  ur- 

Crystallized  Phosphate  of  Lime.  1H6,    IS     USlially     about 


Fig.  14. 


MORBID    URINE.  71 

one  part  in  1000,  varies,  in  disease,  from  a  scarcely  per- 
ceptible trace  to  5*5  in  1000  parts,  and  is  occasionally 
even  higher.  When  present  in  excess,  they  may  gene- 
rally be  partially  precipitated  by  warming  the  urine 
(49). 

110.  It  sometimes  happens,  in  certain  forms  of  disease, 
that  the  earthy  phosphates  are  secreted  in  much  smaller 
quantity  than  is  found  in  healthy  urine,  and  in  some  rare 
cases  they  appear  to  be  altogether  absent.   Whether  this  is 
the  case  in  any  specimen  of  the  secretion,  may  be  ascer- 
tained by  adding  to  it  a  slight  excess  of  ammonia,  when 
if  present  only  in  very  small  proportion,  or  not  at  all, 
no  precipitation  will  take  place ;  or  the  ash  of  the  urine 
may  be  digested  in  dilute  hydrochloric  or  nitric  acid,  and 
the   clear   acid   solution  supersaturated  with  ammonia, 
when,  if  no  precipitate  is  produced,  it  may  be  concluded 
that  no  perceptible  trace  of  earthy  phosphate  is  present. 

II.    Urine  containing  one  or  more  abnormal  ingredients. 

111.  The  abnormal  matters  usually  found  in  morbid 
urine  are:     1,  sugar;*  2,  albumen;  3,  blood;  4,  biliary 
matter;  5,  pus;  6,  fat  and  chylous  matter;  7,  semen;  8, 
oxalate  of  lime ;  9,  cystine  and  other  foreign   matters. 
Besides  the  substances  just  enumerated,  various  others 
may  be  occasionally  detected  in  urine,  such  as  arsenic, 
antimony,  and  many  other  saline  and  organic  matters, 
which  having  been  taken  into  the  system  medicinally  or 
otherwise,    and   being   incapable   of  assimilation,   have 
passed  through  either  unchanged,  or  more  or  less  modi- 
fied in  composition. 

SECTION  X. 

Urine  containing  Sugar  (C^IL^O^. 

i^  i« 

112.  The  variety  of  sugar  always  present  in  the  urine 
of  diabetic  patients,  and  hence  called  diabetic  sugar,  has 
the  same  chemical  composition  as  that  contained  in  most 

*  Recent  researches  (35)  have  removed  sugar  from  the  list  of  strictly 
abnormal  ingredients  of  urine,  but  this  does  not  affect  the  practical 
value  of  the  classification  here  given,  or  of  tests  described  in  the  fol- 
lowing section. 


72  MORBID    URINE. 

kinds  of  fruit,  commonly  known  as  grape  sugar  or 
glucose.  It  appears  to  contain  two  equivalents  of  water 
of  crystallization,  which  may  be  expelled  at  a  tempera- 
ture of  212° ;  so  that  its  composition  may  be  more  cor- 
rectly expressed  by  the  formula  (0^ff^Ol2+^Aq). 

113.  Diabetic  sugar  may  be  obtained  by  concentrating 
the  urine  containing  it,  by  evaporation  on  a  water-bath, 
until  it  begins  to  deposit  a  crystalline  sediment;  the  mass 
is  then  allowed  to  cool,  on  which  the  greater  part  of  the 
sugar  crystallizes  out.     It  is  then  filtered;   and  when 
most  of  the  liquid  has  passed  through,  the  crystals  are 
to  be  pressed  between  folds  of  filtering  paper,  and  washed 
with  a  small  quantity  of  cold  strong  alcohol,  which  serves 
to  remove  the  greater  part  of  the  impurities,  without 
dissolving  much  of  the  sugar.     The  -crystals  are  then 
dissolved  in  hot  water,  and  purified  by  successive  crys- 
tallizations, or,  if  necessary,  by  boiling  with  animal  char- 
coal. 

114.  Diabetic  sugar  differs  from  cane  sugar  (C12HnOn), 
in  being  considerably  less  sweet  to  the  taste,  harder,  and 
less  soluble  in  water ;   one  part  requiring  about  one  and 
a  half  of  cold  water  to  dissolve  it.     In  dilute  alcohol,  on 
the  other  hand,  it  is  somewhat  more  soluble  than  the 
cane  variety;  but  is  insoluble  in  absolute  alcohol  and 
ether.     It  is  usually  in  the   form  of  granular  crystals ; 
but  when  crystallized  out  of  a   considerable    mass   of 
syrup,  is  often  obtained  in  needle-like  tufts.  When  crys- 
tallized from  its  solution  in  dilute   alcohol,   it  usually 
separates  in  the  form  of  hard  transparent  cubes,  and 
occasionally  in  square  plates.* 

115.  Strong  sulphuric  acid  dissolves  grape  sugar,  form- 
ing a  pale  yellowish  solution ;  cane  sugar,  on  the  contrary, 
is  almost  instantly  charred  and  blackened  by  the  strong 
acid. 

116.  Urine  containing  sugar  is  usually  characterized 
by  its  high  specific  gravity,  which  is  frequently  from 
1030  to  1045,  and  occasionally  as  high  as  1050  and  1055. 

*  Volil  has  met  with  a  case  in  which  a  part  of  the  diabetic  -sugar 
in  the  urine  was  replaced  by  inosite.  It  is  also  stated  that  acetone  has 
been  found  in  diabetic  urine. 


URINE    CONTAINING    SUGAR.  73 

If,  however,  the  su<_rar  is  present  only  in  small  quantity, 
the  specific  gravity  may  not  be  higher  than  usual ;  so 
that  a  moderately  low  specific  gravity  is  of  itself  no  proof 
of  the  absence  of  sugar. 

117.  Diabetic  urine  has  usually,  after  standing  a  short 
time  in  a  warm  atmosphere,  a  white   scum,  somewhat 
resembling  flour,  on  the  surface,  consisting  of  minute, 
oval-shaped  confervoid  vesicles  (132),  which  is  highly 
characteristic  of  the  presence  of  sugar,  and  occasionally 
leads  to  its  detection  before  it  has  been  secreted  in  suffi- 
cient abundance  to  raise  the  specific  gravity  of  the  urine 
to  a  suspicious  extent. 

118.  This  variety  of  urine  is  usually  paler  than  the 
natural  secretion,  and  frequently  possesses  a  faint  green- 
ish tint.     It  is  most  commonly  slightly  turbid.     When 
fresh,  it  has  a  faint  and  rather  agreeable  odor,  somewhat 
resembling  that  of  hay. 

119.  The  proportion  of  urea  in  diabetic  urine  is  usually 
much  smaller  than  that  found  in  the  healthy  secretion; 
but  whether  the  absolute  amount  secreted  differs  materi- 
ally from  the  normal  average,  or  whether  the  apparent 
deficiency  is  merely  owing  to  the  large  quantity  of  water 
passed  by  diabetic  patients  thus  largely  diluting  the  urea, 
has  not  yet  been   satisfactorily  decided,  owing  to  the 
difficulty   of  correctly  estimating  the  quantity  of  urea 
when  mixed  with  any  considerable  amount  of  sugar  (334). 

120.  The  proportion  of  sugar  in  diabetic  urine  varies 
from  a  mere  trace  to  from  50  to  80  parts  in  1000;  and  has 
been  known  to  amount  to  as  much  as  134  parts  in  1000. 

121.  Several  tests  have  been  proposed  for  the  detection 
of  sugar  in  urine.    Of  these,  the  following  only  need  here 
be  noticed,  viz.,  Trommels  test,  MaumenSs  test,  Moore's  test, 
the  fermentation  test,  and  the  test  afforded  by  the  growth 
of  a  microscopic  confer  void  vegetation,  called  the  torula. 

122.  Trommei'' 's  test* — This  excellent  test  is  founded 
on  the  circumstance  that  when  a  solution  containing  dia- 

*  If  diabetic  urine  be  not  procurable,  a  few  grains  of  grape  sugar 
maybe  dissolved  informal  urine  for  the  demonstration  of  these  tests. 
Grape  sugar  may  be  obtained  by  boiling  white  sugar  with  water  and 
a  few  drops  of  sulphuric  acid  for  a  few  minutes,  neutralizing  with 
chalk,  filtering  and  evaporating. 

7 


74  MORBID    URINE. 

betic  or  grape  sugar  (112),  is  boiled  with  a  mixture  of 
potash  (K0\  and  sulphate  of  copper  (CuO,S03),  the  oxide 
of  copper  (GuO)  contained  in  the  latter  becomes  reduced 
to  the  state  of  suboxide  (Cu20),  which  is  precipitated  in 
the  form  of  a  reddish  or  ochre-colored  granular  powder. 

123.  A  little  of  the  urine  suspected  to  contain  sugar  is 
placed  in  a  tolerably  large  test-tube,  and  mixed  with  a 
drop  or  two  of  a  solution  of  sulphate  of  copper,  which 
should  be  added  only  in  sufficient  quantity  to  give  the 
mixture  a  very  pale  blue  tint.     This  will  probably  cause 
a  slight  precipitation  of  pale  blue  phosphate  of  copper, 
owing  to  the  presence  of  soluble  phosphates  in  the  urine 
(40) ;  this,  however,  need  not  be  regarded,  as  it  will  not 
afterwards  interfere  with  the  indications  of  the  test.     A 
solution  of  potash  is  now  added  in  large  excess,*  or  in 
quantity  equal  to  about  half  the  volume  of  urine  em- 
ployed ;  this  will  first  throw  down  a  pale  blue  precipitate 
of  hydrated  oxide  of  copper  (CuO,HO),  which,  if  sugar 
is  present,  will  immediately  redissolve,  forming  a  purplish- 
blue  solution,  something  similar  to  that  caused  in  a  very 
dilute  solution  of  copper  by  ammonia. 

124.  The  mixture  is  now  to  be  carefully  heated  over 
a  lamp,  and  gently  boiled ;  when,  if  sugar  is  present,  a 
reddish  or  yellowish  brown  precipitate  of  suboxide  of 
copper  (Cu20)  will  be  deposited  in  the  liquid  generally 
before  the  boiling  point  is  reached.     If  no  sugar  is  pre- 
sent, a  black  precipitate  of  the  common  oxide  of  copper 
(CuO)  will  be  thrown  down,  totally  distinct  in  appearance 
from  the  suboxide.     It  is  important,  in  this  experiment, 
not  to  add  too  much  of  the  sulphate  of  copper,  because, 
in  that  case,  the  suboxide  might  be  mixed  with  some  of 
the  black  oxide  (the  sugar  being  capable  of  reducing  only 
a  certain  definite  quantity),  which  would  more  or  less 
mask  the  characteristic  color  and  appearance  of  the  sub- 
oxide.     This  test  is  extremely  delicate,  and  is  capable  of 
detecting  very  small  traces  of  sugar  in  the  urine.    If  very 
much  sugar  be  present,  the  action  of  the  potash  upon  it 

*  Or  the  potash,  may  be  added,  and  the  solution  filtered  from  any 
deposit  of  earthy  phosphates  that  may  be  thrown  down,  before  the  ad- 
dition of  the  sulphate  of  copper. 


URINE    CONTAINING    SUGAR.  75 

will  produce  a  very  dark  brown  color,  which  may  disguise 
the  suboxide  of  copper.  If  this  be  the  case,  another 
portion  of  the  urine  may  be  diluted  before  being  tested. 
Since  other  substances  are  occasionally  found  in  urine,* 
which  reduce  the  oxide  of  copper,  this  test  cannot  be 
considered  as  conclusive,  except  as  to  the  absence  of 
sugar.  Since  the  presence  of  ammonia  in  any  consider- 
able quantity  interferes  with  this  test,  as  Dr.  Beale  origi- 
nally pointed  out,  recourse  must  be  had  to  the  yeast  test, 
if  much  ammonia  be  smelt  in  this  experiment. 

125.  MaumenSs  test. — This  test  is  founded  on  the  cir- 
cumstance  that  when   sugar   is    moderately   heated    in 
contact  with  the  bichloride  of  tin  (SnCL2),  it  is  decom- 
posed, and  a  brownish  black  compound,  somewhat  resem- 
bling caramel,  is  formed.     The  most  convenient  method 
of  applying   this  test  is  to  saturate  strips  of  merino, 
flannel,  or  some  other  woollen  tissue,  f  with  a  solution  of 
bichloride  of  tin — prepared  by  dissolving  the  salt  in  about 
twice  its  weight  of  water,  and  filtering — after  which  they 
may  be  dried  at  a  gentle  heat  on  a  water-bath,  and  kept 
ready  for  use.     On  moistening  one  of  these  strips  with 
urine,  or  any  other  liquid  containing  sugar,  even  in  a 
highly  diluted  state,  and  holding  it  near  a  fire  or  over  a 
lamp,  so  as  to  heat  it  about  270°  or  300°  Fahr.,  it  imme- 
diately assumes  a  brownish-black  color.    The  delicacy  of 
this  test  is  stated  to  be  so  great  that  though  ordinary 
healthy  urine  causes  no  change  of  color,  if  ten  drops  of 
diabetic  urine  be  diffused  through  half  a  pint  of  water, 
the  mixture  will  immediately  give  decided  indications  of 
sugar. 

126.  Moore's  lest. — Mix  a  little  of  the  suspected  urine  in 

*  Even  uric  acid  produces  the  same  effect,  but  in  general  its  quan- 
tity is  too  small  in  normal  urine  to  allow  of  its  being  mistaken  for 
sugar. 

f  It  is  necessary  in  this  test  to  avoid  the  use  of  cotton  or  linen, 
since  those  substances,  being  analogous  to  sugar  in  composition,  un- 
dergo also  a  similar  decomposition  when  warmed  with  the  bichloride 
of  tin ;  and  would  consequently  become  blackened,  even  though  no 
sugar  were  present.  It  will  be  seen  that  the  utility  of  this  test  depends 
upon  the  circumstance  that  the  prepared  strips  can  be  carried  about 
so  as  to  render  the  tests  available  in  a  clinical  examination.  In  the 
laboratory  the  other  tests  are  more  convenient. 


76  MORBID    URINE. 

a  test-tube,  with  about  half  its  volume  of  liquor  potassa?, 
and  boil  the  mixture  gently  for  a  minute  or  two.  If 
sugar  is  present,  the  liquid  will  assume  a  brownish  or 
bistre  tint,  while  little  or  no  heightening  of  color  takes 
place  when  the  urine  is  free  from  saccharine  matter. 

127.  JBottger's    test. —  Add    to  the   urine   suspected    to 
contain  sugar  a  few  drops  of  a  somewhat  dilute  solution 
of  nitrate  of  bismuth  (BiO3,3NOs)  in  nitric  acid,  then  add 
carbonate  of  soda  till  the  solution  is  alkaline,  and  boil  for 
three  or  four    minutes,  when,  if  sugar  be  present,  the 
mixture  assumes  a  dark  color  from  the  reduction  of  bis- 
muth, and  when  set  aside,  deposits  a  gray  or  black  preci- 
pitate.    With  healthy  urine  a  white  precipitate  of  phos- 
phate and  carbonate  of  bismuth  is  obtained. 

128.  Fermentation  test. — Fill  a  test  tube  with  the  sus- 
pected urine,  having  previously  mixed  with 'it  a  few  drops 
of  fresh  yeast,  or  still  better  a  little  of  the  dried  German 
yeast ;  close  the  open  end  with  a  small  saucer  or  evapo- 
rating dish,  and  while  gently  pressing  the  latter  upon  the 

tube,  invert  them,  when  they  will  be  in 
Fig.  15.  the  position  shown  in  the  figure  (Fig.  15). 

A  little  more  of  the  urine  is  then  poured 
into  the  saucer  in  order  to  prevent  the 
escape  of  any  of  the  liquid  from  the  tube; 
and  if  any  bubbles  of  air  have  accidentally 
been  allowed  to  enter,  the  exact  height  of 
the  upper  surface  of  the  liquid  in  the  tube 
must  be  marked  with  ink,  or  with  a  strip 
of  gummed  paper.     The  tube,  with    its 
Fermentation  test,      contents,  is  then  set  aside  in  a  warm  place, 
having  a  temperature  of  about  70°  or  80°, 
for  twenty-four  hours.     As  bubbles  of  gas  are  sometimes 
given  off  by  the  yeast  itself,  it  is  a  good  precaution  to  put 
the  same  quantity  of  yeast  into  a  second  tube  of  equal 
size,  and  fill  it  up  with  pure  water.     The  amount  of  gas, 
if  any,  derived   from  the  yeast,  will  thus  be  rendered 
apparent,  and  may  "afterwards  be  deducted  from  the  vol- 
ume of  gas  in  the  tube  containing  the  urine. 

129.  If  sugar  is  present,  it  begins  almost  immediately 
to  undergo  the  vinous  fermentation,  by  which  it  becomes 
converted  into  alcohol  (C^O^HO)  and    carbonic  acid 


URINE    CONTAINING    SUGAK.  77 

(COJ,  each  equivalent  of  sugar  giving  rise  to  the  forma- 
tion of  two  equivalents  of  alcohol,  four  of  carbonic  acid, 
and  two  of  water,  thus:  — 


The  carbonic  acid  thus  formed  rises  in  minute  bubbles, 
causing  gradual  and  general  effervescence,  and  collects  in 
the  upper  part  of  the  tube  ;  at  the  same  time  displacing 
the  liquid,  which  escapes  through  the  open  end  of  the 
tube  into  the  saucer.* 

130.  That  the  gas  thus  formed  is  really  carbonic  acid, 
may  be  proved  by  decanting  a  little  of  it  under  water 
into  a  clean  tube,  and  testing  it  with  lime-water,  which 
will  instantly  become  milky,  owing  to  the  formation  of 
the  insoluble  carbonate  of  lime  (CaO,CO2).     When  the 
quantity  of  sugar  present  is  at  all  considerable,  the  urine, 
after  fermentation,  will  be  found  to  possess  a  faint  vinous 
smell,  due  to  the  alcohol  formed  during  the  process. 

131.  If,  on  the  contrary,  the  urine  is  free  from  sugar, 
of  course  no  fermentation  will  take  place,  and  no  gas  will 
be  formed  in  the  tube. 

132.  Test  afforded  by  the  growth  of  the  torula.  —  During 
the  process  of  the  vinous  fermentation  of  a  liquid  con- 
taining sugar,  a  delicate  white  scum  gradually  collects  on 
the  surface,  which,  when  seen  merely  with  the  naked  eye, 
is  so  highly  characteristic  an  indication  of  the  presence 
of  sugar,  as  frequently  to  lead  to  its  detection  when  pre- 
sent only  in  very  small  quantity.     If  a  little  of  this  scum 
be  examined  under  the  microscope,  with  a  magnifying 
power  of  four  or  five  hundred  diameters,  it  will  be  found 
to  consist  of  minute  oval  vesicles  (Fig.  16),  which  in  the 
course  of  a  few  hours  rapidly  change  their  form,  becom- 
ing longer  and   more  tubular,  and   giving  rise  to  new 
vesicles,  which  shoot  out  from  the  parent  body,  forming 
an  irregularly  jointed  confervoid  stem  (Fig.  17).     These 
again  gradually  break  up  into  a  great  number  of  oval 
vesicles,  which  eventually  separate,  and  fall  to  the  bottom, 
where  they  may  be  detected  by  microscopic  examination. 

*  This  has  been  lately  proved  to  be  only  one  of  the  changes  whiVh 
are  involved  in  the  fermentation  of  sugar,  other  substances,  such  as 
succinic  acid  and  glycerine,  ln-iu^  formed  at  the  same  that-. 

7* 


78  MORBID    URINE. 

Fig.  16.  Fig.  17. 


m. 


Torula  Vesicles,  magnified  400  diameters.  Torala  Stem. 

Precipitation  by  trlbasic  acetate  of  had  and  ammonia. — 
When  the  proportion  of  sugar  present  in  urine  is  very  mi- 
nute, the  best  process  for  extracting  it  consists  in  precipi- 
tating the  urine,  first  with  acetate  of  lead,  then  with  tribasic 
acetate  of  lead  added  in  excess,  and  lastly,  after  filtering, 
with  ammonia.  This  last  precipitate  is  collected  upon  a 
filter,  washed,  suspended  in  water,  and  decomposed  by 
sulphuretted  hydrogen.  After  filtering  from  the  sulphide 
of  lead,  and  evaporating,  the  sugar  may  be  detected  by 
any  of  the  tests  above  described.* 

Precipitation  by  potash  and  alcohol. — If  urine  contain- 
ing sugar  be  mixed  with  four  volumes  of  absolute  alco- 
hol, allowed  to  stand  for  some  time,  filtered,  mixed  with 
a  little  alcoholic  solution  of  potash,  and  set  aside  for  a 
day  or  two,  a  combination  of  grape-sugar  with  potash 
separates  as  a  deposit  which  adheres  to  the  side  of  the 
vessel.  The  alcoholic  liquid  having  been  drained  off', 
the  deposit  may  be  dissolved  in  water,  and  tested  by  any 
of  the  above  tests.f 

132#.  A  very  remarkable  substance  has  occasionally 
been  observed  in  urine,  which  answers  to  the  test  with 
the  alkaline  copper  solution  in  precisely  the  same  man- 
ner as  sugar,  but  does  not  possess  the  property  of  re- 

*  This  process  has  been  employed  for  the  demonstration  of  the  pre- 
sence of  sugar  in  normal  urine,  but  the  circumstance  that  the  indigo- 
producing  body  described  by  Schunck  (36)  is  precipitated  in  the  same 
way,  and  yields  sugar  as  a  product  of  its  decomposition,  much  dimi- 
nishes the  value  of  the  evidence  which  it  affords. 

f  According  to  Brucke.  sugar  may  be  detected  in  healthy  urine  by 
this  process. 


IT  RINK    CONTAINING    ALP.l'MKX.  79 

ducing  the  oxide  of  bismuth,  or  of  fermenting  in  contaet 
with  yeast.  Its  most  striking  feature  is  that  of  absorb- 
ing oxygen  from  the  air,  and  producing  a-  brown  color, 
when  an  alkali  is  added  to  the  solution  containing  it,  so 
that  urino  in  which  this  substance  is  present  becomes 
brown  at  once  when  shaken  with  potash,  whilst  saccha- 
rine urine  does  not  become  brown  until  it  is  boiled. 
Boedeker,*  who  first  directed  attention  to  this  substance, 
which  he  named  alkapton,  has  isolated  it  in  the  following 
manner:  The  urine  was  precipitated  by  acetate  of  lead 
and  filtered.  The  filtrate  was  mixed  with  tribasic  ace- 
tate of  lead,  avoiding  an  excess,  the  precipitate  washed, 
suspended  in  water,  and  decomposed  by  sulphuretted 
hydrogen.  The  solution  filtered  from  the  sulphide  of 
lead  was  evaporated  to  dryness  on  the  water-bath,  and 
the  residue  extracted  with  ether.  On  evaporating  the 
ethereal  solution,  the  alkapton  was  obtained  as  a  golden- 
yellow,  resinous,  deliquescent  substance,  very  easily  so- 
luble in  water  and  alcohol.  Its  solution  reddens  litmus 
slightly,  and  is  unchanged  by  exposure  to  air,  unless  an 
alkali  is  added.  The  precipitate  produced  by  tribasic 
acetate  of  lead,  also  becomes  brown  when  exposed  to 
the  air.  Alkapton  contains  nitrogen,  but  its  exact  com- 
position has  not  yet  been  ascertained.! 

SECTION  XI. 
Urine  containing  Albumen.^ 

133.  This  substance,  which  is  contained,  as  is  well 
known,  in  large  quantity  in  many  of  the  tissues  of  the 
body,  and  especially  in  the  serum  of  the  blood  (466),  is 
not  unfrequently  present  in  morbid  urine.  Albuminous 
urine  varies  very  considerably  in  appearance  and  general 
characters,  being  found  alkaline,  acid,  and  neutral;  high 
colored,  and  pale;  of  high  specific  gravity  and  the  con- 

*  Ann.  Ch.  Pharm.,  January,  1861. 

f  Dr.  Johnson  has  observed  the  occurrence  of  alkapton  in  the  urine 
of  an  infant,  his  attention  being  called  to  it  by  the  brown  stains  pro- 
duced on  the  linen. 

\  For  the  purpose  of  demonstrating  the  tests,  a  very  little  well- 
"beaten  white  of  eetr  may  be  mixed  with  some  normal  urine. 


80  MORBID    URINE. 

trary;  so  that  no  general  rule  can  be  laid  down  as  to  its 
usual  physical  peculiarities,  likely  to  lead  to  its  detec- 
tion; though,  when  its  presence  is  once  suspected,  its  de- 
tection is  easy  and  simple  (139). 

134.  The  quantity  of  albumen  found  in  urine  varies 
very  much;  a  mere  trace  only  being  sometimes  present, 
and  at  others  as  much  as  ten  or  twelve  parts  in  1000. 

135.  The  most  remarkable  property  of  albumen  is, 
that  when  a  solution  containing  it  is  heated  to  a  tempera- 
ture of  about  170°,  or  higher,  it  coagulates,  and  separates 
completely  from  the  liquid ;  and  when  this  change  has 
once  taken  place,  it  becomes  quite  insoluble  in  water. 
The  coagulated  albumen  is  readily  soluble  in  potash  and 
other  alkaline  solutions;  and  when  an  excess  of  alkali  is 
present;  no  coagulation  takes  place  on  boiling. 

136.  Albumen  is   precipitated  from   its   solution  by 
nitric  and  hydrochloric  acids,  but  not  by  phosphoric, 
acetic,  or  tartaric  acids,  which,  indeed,  appear  to  exercise 
a  decided  solvent  action  upon  it,  and,  when  present,  pre- 

.  vent  its  coagulating  on  the  application  of  heat. 

137.  It  is  also  readily  precipitated,  even  from  an  acetic 
acid  solution,  by  ferrocyanide  (KyFeCy3-\-%Aq)  and  ferrid- 
cyanide  (KyFe2Cy6)  of  potassium;  and  the  precipitates 
thus  formed  are  easily  soluble  in  alkaline  solutions.      0J 

138.  Chloride  of  mercury  (HgCl\  alum  (A1203,SS03 
+  KO,/S03+24:Aq),  and  many  other  of  the  metallic  salts, 
also  cause  precipitates  in  albuminous  solutions,  which  are 
compounds  of  the  salt  with  albumen.     It  is  precipitated, 
too,  by  alcohol,  creasote,  tannin,  and  many  other  sub- 
stances. 

139.  The  detection  of  albumen  in  urine  containing  it 
is  very  easy.     The  suspected  urine  may  be  gently  boiled 
in  a  test-tube,  when,  if  albumen  is  present,  it  will  coagu- 
late, and  form  a  more  or  less  copious  white  precipitate. 
If  the  albumen  is  present  only  in  minute  quantity,  it  may 
cause  merely  a  delicate  opalescence;  or,  when  in  larger 
quantity,  it  may  separate  in  curdy  flakes;  and  if  very 
abundant,  may  cause  the  liquid  to  gelatinize,  and  become 
nearly  solid  (142). 

140.  The  appearance  of  a  white  precipitate  on  boiling 
is  not,  however,  of  itself,  a  sure  proof  of  the  presence  of 


URINE    roXTAlXIXii    AUJIJMKX.  81 

albumen  in  urine,  sinoo  a  white  precipitate  is  also  pro- 
duced by  boiling,  when  the  secretion,  free  from  albumen, 
contains  an  excess  of  earthy  phosphates  (49a).  It  is 
therefore  necessary  to  add  a  few  drops  of  nitric  acid, 
which,  in  case  the  precipitate  consists  of  phosphates,  im- 
mediately redissolves  it,  but  if  albuminous,  leaves  it  still 
insoluble. 

141.  To  prevent  the  possibility  of  error,  it  is  always 
advisable  to  test  a  separate  portion  of  the  urine  also  with 
dilute  nitric  acid,  by  which  the  albumen,  if  present,  will 
instantly  be  thrown  down.     If  the  quantity  of  albumen 
is  very   small,  it   is   possible   that   the   milkiness   first 
caused  by  the  acid  may  disappear,  but  if  a  few  drops 
more  of  the  acid  be  added,  the  precipitate  will  again 
separate,  and  remain  insoluble.     If  both  heat  and  nitric 
acid  cause  a  white  precipitate,  there  can  be  no  doubt  of 
the  presence  of  albumen. 

141«.  The  coagulum  may  be  further  tested  by  Ninon's 
test,  which  consists  in  gently  heating  it  with  solution  of 
nitrate  of  mercury  (HgO,N05)  prepared  by  dissolving 
200  grains  of  mercury  in  5  drachms  of  ordinary  concen- 
trated nitric  acid,  with  the  aid  of  heat.  Albumen  ac- 
quires an  intense  red  color  when  heated  with  this  solu- 
tion, whilst  normal  urine  is  only  rendered  faintly  and 
transiently  pink.  Fibrin,  casein,  and  other  members  of 
the  same  group  of  bodies  (protein  compounds)  exhibit 
the  same  behavior. 

142.  In  testing  for  albumen,  it  must  be  borne  in  mind 
that,  if  the  liquid  is  alkaline  to  test-paper,  the  albumen, 
though  present,  will  probably  not  be  coagulated  on  the 
application  of  heat,  since  coagulated  albumen  is  readily 
soluble  in  alkaline  solutions  (135).     On  this  account  the 
nrine  should  first  be  examined  with  turmeric  or  reddened 
litmus  paper  (277),  and,  if  found  to  be  alkaline,  neutral- 
ized with  nitric  acid  before  boiling. 

143.  It  should  also  be  remembered  that  when  the  al- 
bumen is  present  only  in  small  quantity,  the  addition  of 
a  very  slight  excess  of  nitric  acid  may  redissolve  it,  and 
thus  lead  to  the  supposition  that  the  precipitate  is  phos- 
phatic.     A  few  drops  more  of  the  acid,  however,  will  in- 
stantly cause   it   to   reappear,  if  albuminous;    while,  if 


82  MORBID    URINE. 

really  phospbatic,  no  excess  of  the  acid  would  cause  it 
to  do  so.* 

144.  The  peculiar  casts  of 
Fig.  18.  urinary  tubes,  found    in    the 

urine  of  patients  suffering 
from  B right's  disease,  con- 
sisting  of  fibrinous  or  albu- 
cast.  (Dr.  G.  Johnson.)  minous  matter,  and  entang- 
ling blood  corpuscles,  epithe- 
lium, and  fatty  globules,  have  usually  the  appearance 
shown  in  figure  18.f 

SECTION  XII. 
Urine  containing  Blood. 

145.  Urine  frequently  contains,  in  addition  to  albumen, 
one  or  more  of  the  other  constituents  of  the  blood  (450), 
and  is  often  more  or  less  highly  colored  red  or  brown, 
by  the  presence  of  the  corpuscles  and  red  coloring  mat- 
ter.    When  the  fibrin,  in  its  soluble  form,  is  present,  it 
usually  coagulates  spontaneously  on  cooling,  and  causes 
the  urine  to  become  more  or  less  gelatinous  soon  after  it 
is  passed.     This  spontaneous  coagulation  on  cooling  may 
be  considered  of  itself  sufficient  proof  of  the  presence  of 
the  fibrin  of  the  blood. 

146.  The  blood  corpuscles  may  generally  be  detected 
'both  in  the  coagulurn  and  also  in   the  superincumbent 
fluid,  when  examined  under  the  microscope  (451) ;  occa- 
sionally, however,  they  are  almost  entirely  disintegrated, 
so   that  little   or  no  trace  of  their   characteristic   form 
remains.     They  are  sometimes  found  adhering  together, 

*  The  result  of  these  tests  for  albumen  ma/ be  confirmed  by  acidu- 
lating another  portion  of  urine  with  acetic  acid,  and  adding  ferrocya- 
nide  of  potassium  (137).  Chloride  of  mercury  may  be  added  to  ano- 
ther portion  (138). 

In  a  case  of  mollities  ossium,  an  albuminoid  substance  has  been 
observed  in  the  urine,  which  was  precipitated  by  nitric  acid  like  albu- 
men, but  the  coagulum  dissolved  on  heating,  and  reappeared  as  the 
solution  cooled.  Ferrocyanide  of  potassium  also  precipitated  this 
substance.  Tannic  acid  gave  a  precipitate  in  this  urine. 

|  The  presence  of  inosite  in  the  urine  has  been  noticed  in  a  case  of 
Bright's  disease. 


URINK    CONTAINING    BILIARY    MATTER.          83 

forming  little  thread-like  aggrega-  Fis- 19. 

tions  ;  but  more  frequently  floating 

detached  from  each  other,  looking 

like  little   transparent  rings   (Kig. 

19). 

147.  In  urine  containing  blood, 
the  albumen   may  in  all  cases  be 
readily  detected  by  the  tests  already 

mentioned   (139)  —  viz.,   heat    and      

nitric  acid ;    but  when  any  of  the  Blood  in  urine, 

coloring  matter  of  the  blood  is  also 

present,  it  will  coagulate  with  the  albumen,  giving  the 
coagulum  a  more  or  less  decided  red  or  brown  color. 

SECTION  XIII. 
Urine  containing  Biliary  matter.* 

148.  When  biliary  matter  is  present  in  urine,f  it  gene- 
rally gives  a  more  or  less  decided  yellowish  brown  color, 
both  to  the  liquid  and  also  to  any  sediment  that  may  be 
deposited  from  it.    The  taste  also  of  such  urine  is  remark- 
ably bitter — a  peculiarity  which  furnishes  a  ready  indi- 
cation of  its  presence  when  other  tests  are  not  at  hand  ; 
though  it  must  not  be  implicitly  relied  on,  since  small 
traces  may  exist  in  the  secretion,  without  communicating 
to  it  any  very  decided  taste. 

149.  Pettenkofer's  test.     Perhaps  the  best  test  for  the 
presence  of  bile,  is  that  known  as  Pettenkofer's.     If  the 
urine  contains  albumen,  it  should  first  be  freed  from  that 
substance  by  coagulation  and  filtration  (135,  151);  be- 
cause albumen,  when  present  in  considerable  quantity, 
would  give,  with  sulphuric  acid  and  sugar,  a  color  re- 
sembling that  caused  by  bile.     Dissolve  a  grain  or  two 
of  white  sugar  in  the  urine  to  be  tested,  and  add,  drop 
by  drop,  about  two-thirds  of  its  volume  of  strong  sul- 
phuric acid.   If  biliary  matter  be  present,  a  very  distinct 
and  characteristic  violet-red  color  will  be  produced,  which 

*  A  little  ox-gall  may  be  added  to  tlie  urine  for  the  purpose  of  ap- 
plying the  tests. 

f  According  to  Scherer,  biliary  coloring  matter  is  occasionally  pre- 
sent in  healthy  urine. 


8-4  MORBID    U1UNE. 

becomes  redder  and  more  intense  on  the  application  of 
heat.  A  very  small  quantity  of  the  biliary  matter  re- 
sponds to  this  test;  but  a  still  more  delicate  mode  of  ap- 
plying it  consists  in  mixing  the  urine  with  a  single  drop 
of  dilute  sulphuric  acid  (1  part  of  acid  to  4  of  water), 
adding  a  trace  of  a  solution  of  sugar,  containing  10  per 
cent.,  and  evaporating  at  a  gentle  heat,  when  the  violet 
color  becomes  evident. 

150.  When  the  quantity  of  bile  is  small,  it  is  advisable, 
before  applying  the  test,  to  concentrate  the  urine  by  eva- 
poration.    For  this  purpose  it  is  first  boiled,  in  order  to 
coagulate   any  albumen  that  may  be  present  (151),  and 
afterwards  evaporated  nearly  to  dryness  on  a  water-bath. 
The  residue  is  then  treated  with  a  small  quantity  of  boil- 
ing water  or  alcohol ;  and  the  solution  thus  formed,  con- 
taining any  biliary  matter  that  may  be  present,  is  allowed 
to  cool  and  tested  as  above. 

151.  The  experiment  known  as  Heller's  test  is  made  as 
follows:  Mix  with  a  little  of  the  suspected  urine  a  few 
drops  of  the  serum  of  blood  or  white  of  egg,  or  of  any 
liquid  containing  albumen  in  solution ;  and  having  shaken 
them  well  together,  add  a  slight  excess  of  nitric  acid, 
which  will  cause  the  precipitation  of  the  albumen  (136). 
If  bile  is  present,  the  coagulum  thrown  down  by  the  acid 
will  have  a  more  or  less  distinct  dull  green  or  bluish 
color,  quite  different  from  the  white  or  pale  fawn  color 
which  it  would  otherwise  have.     When  only  a  small 
quantity  of  biliary  matter  is  present,  the  urine  may  be 
concentrated,  as  in  Pettenkofer's  test  (150),  the  serum  or 
white  of  egg  being  subsequently  added  to  the  cold  con- 
centrated aqueous  solution  of  the  evaporated  residue. 

152.  Grmelin's  test. — Pour  a  few  drops  of  the  suspected 
urine  upon  a  clean  white  plate  or  dish,  so  as  to  form  a 
thin  layer  of  the  liquid,  and  then  carefully  drop  into  the 
centre,  with  a  pipette,  five  or  six  drops  of  nitric  acid. 
When  bile  is  present  in  any  considerable  quantity,  the 
liquid  becomes  successively  pale  green,  violet,  pink,  and 
yellow,  the  color  rapidly  changing  as  the  acid  mixes  with 
the  urine.     When  the  bile  is  present  only  in  small  quan- 
tity, these  colors  are  not  distinctly  visible;  but  unless 
the  proportion  is  very  minute,  a  greenish  tint  is  generally 


URINE    CONTAINING    PUS.  85 

perceptible.  On  concentrating  the  urine  by  evaporation, 
the  appearance  may  be  seen  to  greater  advantage  when 
only  small  traces  of  bile  are  present  (150).  The  action  of 
this  test  appears  to  depend  on  the  presence  of  the  pecu- 
liar brown  coloring  matter  of  bile,  called  biliphaein,  or 
cholepyrrhin.* 

SECTION  XIV. 
Urine  containing  Pus. 

153.  Pus  is  a  substance  which  in  many  respects  closely 
resembles  mucus,  both  in  its  behavior  with  reagents,  and 
still  more  in  its  appearance  under  the  microscope;  so 
that  it  is  not  always  easy  to  distinguish  between  them; 
and  when  mixed  together  in  the  urine,  it  is  frequently 
quite  impossible  to  say  with  certainty 

whether  or  not  both  are  present.    Like  FiS-  20- 

mucus,  it  consists  of  minute  round  or         @>  r?$\  ® 
oval    granular    corpuscles    (Fig.    20),      ©      /aPfo   ® 
floating  in  the  fluid,  from  which  they         ^8  ^    ~ 
separate   on   standing,   and   gradually  (^    (§)  ^ 

sink  to  the  bottom.  These  form,  in  ^£|) 
urine  containing  pus,  a  pale  greenish-  Pus  ^ 
yellow  or  cream-colored  layer,  at  the  4oodiam. 

bottom  of  the  fluid  ;  and,  if  shaken,  the 
sediment  readily  breaks  up,  and  diffuses  itself  through 
the  liquid,  again  gradually  subsiding  to  the  bottom  when 
allowed  to  stand.  If  the  urine,  however,  be  decidedly 
alkaline,  the  character  of  the  purulent  deposit  is  changed, 
and  it  assumes  nearly  the  same  appearance  as  mucus 
(251,  680). 

154.  Urine  containing  pus  is  met  with  sometimes  neu- 
tral, acid,  and  alkaline.     It  always  contains  albumen  in 
solution,  which  may  be  recognized  in  the  filtered  urine 
by  the  usual  tests,  heat  and  nitric  acid  (139).     This  albu- 
men is  derived  from  the  liquor  puns,  in  which  it  is  always 


*  Briicke  recommends  a  useful  modification  of  this  test,  which  con- 
sists in  mixing  the  urine  in  a  tube  witli  dilute  nitric  acid,  and  carefully 
pouring  in  sulphuric  acid,  so  as  to  form  a  layer  at  the  bottom  of  the 
urine.  The  rings  of  color  commence  from  the  junction  of  the  two 
lavers. 

8 


86 


MORBID    URINE. 


Fig.  21. 


present  (254,  677).  The  absence  of  albumen,  therefore^ 
in  the  urine,  may  be  considered  as  a  strong  indication  of 
the  absence  of  pus;  though  the  presence  of  albumen  is  of 
itself  no  kind  of  proof  of  the  existence  of  pus,  since  it 
may  be  derived  from  other  independent  sources.  Traces 
of  blood  are  by  no  means  unfrequent  in  purulent  urine, 
giving  the  sediment  a  brown  or  reddish  color  (145). 

155.  The  chemical  and  microscopic  characters  of  pus, 
and  the  modes  of  distinguishing  it  from  mucus,  will  be 
more  fully  described  further  on  (247  to  258,  674). 

156.   The  peculiar  granular  cor- 
puscles, which  have  been  called  large 
organic  globules,  and  which  are  not 
unfrequently  met   with   in   certain 
conditions  of  the  urine,  especially  in 
that  of  pregnant  women,  closely  re- 
semble the  corpuscles  of  mucus  and 
pus,  being  granular  on  the  exterior, 
and,  on  the  addition  of  acetic  acid, 
Large  organic  Globules,    develop  internal  nuclei.     They  are, 
magnified  400  diameters.        however,  larger,  and  are  unaccom- 
panied by  the  albuminous  and  viscid 
fluids,  which  are  characteristic  respectively  of  pus  and 
mucus  (676,  661).     The  general  appearance  is  shown  in 


Fig.  21. 


Fig.  22. 


Small  Organic  Globules. 


157.  The  small  circular  bodies, 
which  have  been  occasionally,  though 
much  more  rarely,  found  in  certain 
morbid  conditions  of  the  secretion, 
and  called  small  organic  globules, 
are  represented  in  Fig.  22.  They 
are  spherical  and  smooth  on  the 
surface,  no  appearance  of  granular 
structure  being  apparent,  and  con- 
siderably smaller  than  the  large 
organic  globules  (156).  They  are 
unaffected  by  acetic  acid. 


URINE    CONTAINING    CHYLOUS    MATTER.         87 

SECTION  XV. 
Urine  containing  Fat  and  Chylous  matter. 

158.  Urine  containing  fatty  or  cliylous  matter  is  usually 
more  or  less  turbid,  and  frequently  has  an  almost  milky 
appearance.     Little  is  known  as  to  the  precise  nature  of 
the  fatty  matter  which  is  thus  occasionally  met  with  in 
urine,  though  it  is  probable  that  its  composition  varies 
with  the  circumstances  under  which  it  is  formed.     It 
sometimes  exists  associated  with  albumen  and  chylous 
matter,  sometimes  alone.   Numerous  minute  oily  globules 
may  in  many  cases  be  seen  under  the  microscope  (325), 
but  it  is  often  so  intimately  mixed  with  the  albuminous 
matter  also  present,  forming  a  kind  of  emulsion,  that  no 
trace  of  oily  globules  can  be  detected  even  with  a  high 
magnifying  power.     In  such  cases,  the  urine  may  be 
agitated  with  a  little  ether,  which  will  dissolve  the  fat ; 
and  the  ethereal  solution  thus  formed  will  separate  from 
the  watery  liquid,  forming  a  distinct  stratum  floating  on 
the  surface.     If  the  ethereal  solution  be  evaporated  at  a 
gentle  heat,  the  fat  will  be  left,  and  may  be  readily  re- 
cognized by  the  physical  peculiarities  of  fatty  substances ; 
such   as   immiscibility  with    water;    breaking   up   into 
minute  globules  when  agitated  with  hot  water,  &c.  Fibrin 
is  said  to  be  discoverable  in  urine  of  this  description. 

Chylous  urine  frequently  contains  minute  round  cor- 
puscles, resembling  the  white  globules  of  the  blood  or 
lymph,  which  at  first  sight  have  a  good  deal  the  appear- 
ance of  oil  globules,  for  which  they  have  probably  been 
in  some  cases  mistaken.  Their  insolubility  in  ether, 
however,  shows  that  they  are  not  always  composed  of 
fatty  matter. 

159.  The  peculiar  form  of  mucilaginous  or  caseous 
matter,  usually  present  in  the  urine  of  pregnancy,  and 
which  has  received  the  name  of  Kiestein,  gives  the  urine 
containing  it  a  cloudy  appearance ;  and  after  the  lapse 
of  a  few  days,  gradually  forms  on  the  surface  a  more  or 
less  shining  pellicle,  which  in  three  or  four  days,  as  the 
urine  becomes  ammoniacal,  breaks  up  into  minute  par- 
ticles, which  subside  to  the  bottom.     When  examined 
under  the  microscope,  the  pellicle  is  found  to  consist  of 


88 


MORBID    URINE. 


(.23. 


minute  granular  particles,  usually  mixed  with  great 
numbers  of  prismatic  crystals  of  triple  phosphate  (44),  to 
which  latter  the  peculiar  shining  appearance,  somewhat 
resembling  spermaceti,  seems  to  be  due.  A  few  globules 
of  oily  matter,  resembling  butter,  are  also  occasionally 
present.* 

Cholesterin  has  been  found  in  urine  in  Bright's  dis- 
ease by  Dr.  Beale. 

SECTION  XVI. 
Urine  containing  Semen. 

160.  When  semen  is  present  in  urine,  it  may  easily  be 
detected  under  the  microscope,  by  the  appearance  of  mi- 
nute  animalcules,  always 
found    in    the    spermatic 
fluid,  and  hence  called  sper- 
matozoa. •  They  are  more 
or  less  oval  in  form,  and 
are   furnished    with   long 
and  delicate  tails,  as  shown 
in  Fig.  23.     These   sper- 
matozoa,   while    in    their 
native  fluid,  enjoy  an  ac- 
tive existence,  and  move 
about  at  will.     In  urine, 
however,  unless  a  consi- 
derable quantity  of  pus  is 

also  present,  they  are  never  found  alive,  the  secretion 
proving  apparently  fatal  to  them. 

161.  In  addition  to  the  spermatozoa,  there  may  gene- 
rally be  recognized  in  seminal  urine  a  few  minute  granular 
corpuscles,  of  a  round  or  oval   form  (a,  Fig.  23),  and 
rather  larger  than  the  bodies  of  the  animalcules.     Traces 
of  albumen  also  may  generally  be  detected  in  urine  con- 
taining semen  (264). 

*  Since  Kiestein  is  not  a  definite  substance,  but  merely  a  deposit^ 
of  a  fungoid  growth,  together  with  triple  phosphate,  consequent  upon 
the  rapid  alkalescence  of  the  urine,  it  is  not  regarded  as  a  conclusive 
evidence  of  pregnancy. 


Spermatozoa,  and  Spermatic  Granules, 
magnified  400  diameters. 


URINE    CONTAINING    OXALATE    OF    LIME.        89 

SECTION   XVII. 
Urine  containing  Oxalate  of  Lime  (CaO,C3O3-f  2Aq). 

102.  Urine  containing  much  oxalate  of  lime  is  usually, 
though  by  no  means  always,  of  a  dark  amber,  and  often 
of  a  pale  greenish,  or  citron  color.     It  is  in  most  cases 
decidedly  acid  to  test-paper,  and  is  frequently  found  to 
contain  an  unusually  large  quantity  of  epithelial  debris. 
It  often  contains  an  excess  of  uric  acid  and  urates,  and 
almost  invariably  also  an  abnormally  large  quantity  of 
urea.    Its  specific  gravity  is  not  often  materially  different 
from  that  of  the  healthy  secretion,  viz.,  about  1020. 

103.  Oxalate  of  lirne  appears  to  exist  very  frequently 
in  urine,  generally  in  the  form  of  minute  and  well-defined 
octohedral  crystals  (Fig.  24) ;  but  unless  carefully  looked 
for,  it  may  readily  escape  detection,  owing  to  the  crystals, 
which  are  very  transparent,  having  almost  exactly  the 
same  refractive  power  as  the  urine  itself,  so  that  it  is  not 
always  easy  to  distinguish  them  as  they  float  in  the  liquid. 
The  crystals  have  also  nearly  the  same  specific  gravity 
as  urine,  in  consequence  of  which  they  generally  remain 
suspended  in  the  fluid  some  considerable  time,  before 
they  form  a  sedimentary  deposit  at  the  bottom  of  the  con- 
taining vessel. 

104.  The  best  way  of  detecting  them  is  to  allow  the 
urine  suspected  to  contain  them  to  stand  a  few  hours, 
that  the  oxalate  may,  in  some  measure,  subside ;  though 
frequently  it  remains  several  days  without  doing  so  com- 
pletely, in  which  case  the  urine  may  be  passed  through 
a  filter,  when  most  of  the  crystals  will  be  retained  by  the 
paper,  and  may  be  warmed  with  a  little  distilled  water, 
in  the  manner  described  below  (105).     The  greater  part 
of  the  liquid  is  then  carefully  poured  off,  and  the  lower 
stratum  is  placed  in  a  watch-glass  or  small  porcelain  dish 
and  gently  heated  over  a  lamp.     In  this  way  the  liquid 
will  become  specifically  lighter,  and  in  consequence,  the 
crystals,  if  present,  will  gradually  subside  to  the  bottom, 
especially  if  a  slight  rotatory  motion   be  given  to  the 
liquid.     It  is  now  allowed  to  stand  a  few  minutes,  and 
the  clear  liquid  is  carefully  poured  off,  or  removed  by 
moans  of  a  pipette. 


90  MORBID    URINE. 

165.  A  little  distilled  water  may  now  be  added,  when 
the  sediment  will  become  much  more  distinctly  visible, 
owing  to  the  refractive  power  of  the  water  differing  more 
decidedly  from  that  of  the  crystals.  The  mixture  is 
again  heated,  when  any  urate  of  ammonia,  which  is  often 
also  present,  will  be  dissolved ;  and  by  pouring  off  the 
liquid,  after  standing  a  few  minutes,  the  crystals  will  be 
left  at  the  bottom,  and  may  be  removed  for  the  purpose 
of  microscopic  examination,  or  for  testing  with  reagents. 

166.  Oxalateof  lime, 

Fig-  24-  as  found  in  the  urine, 

is  usually  in  the  form 
of  beautifully  defined 
octohedral  •  crystals 
(Fig.  24),  of  sizes  vary- 
ing from  7J3  to  sgVflth 
of  an  inch  in  diameter. 
When  examined  with 

Octohedral  Crystals  of  Oxalate  of  Lime.  polarized     light,     these 

octohedra  will  be  found 

to  have  little  or  no  action  upon  it,  and  remain  invisible, 
or  nearly  so,  when  the  field  is  dark. 

167.  When  allowed  to  dry  upon 
Fig-  25-  the  glass,  each  crystal  appears  under 

SL          *  the  microscope,  especially  if  the  mag- 

nifying  power  is  not  very  high,  like 
a  black  cube,  having  in  the  centre  a 
small  white  square  opening,  as  shown 
in  Fig.  25.  This  curious  appearance 
is  owing  to  the  rays  of  light,  from  the 
greater  part  of  the  crvstal  being;  re- 

Octohedra  of  Oxalate  of       °  *~  ..          £  „       P  . 

Lime ;  seen  when  dry.      fracted  beyond  the   field   of  vision. 
On  again  moistening  them,  the  crys- 
tals reappear  as  before  in  their  true  octohedral  form. 

168.  Oxalate  of  lime  is  not  unfrequently  met  with  in 
the  urine,  having  the  forms  shown  in  Fig.  26,  more  or 
less  resembling  dumb-bells,  with  finely  striated  surfaces. 
This  form  of  oxalate-of-lime  sediment,  unlike  the  octo- 
hedral variety  (166),  appears  beautifully  colored  and  stri- 


U&INE    CONTAINING    OXALATE    OF    LIME.        91 

ated  when  examined  with  polarized  *%•  26- 

light.*    If  these  "dumb-bells"  be  kept  ^    ^ 

in  any  liquid  medium  for  a  length  of  (j^>    '  •"  ^\A 

time,  they  gradually  pass  into  octo-  ^.  ^ft  ™ 

hedra,  which  is  their  more    natural  5^   w  «K  ^ 

form ;  so  that  when   it  is  wished  to  <>  @Lfa  \» 
preserve  the  dumb-bells,  they  should  ^^  ^ 

be  put  up  in  balsam  in  which  they 

f  .      .  ..  J  Dumb-bolls  of  Oxalate 

will  continue  to  retain  their  peculiar  of  Lime, 

form.  There  are  occasionally  to  be 
seen,  also,  mixed  with  the  octohedra  and  dumb-bells,  a 
few  minute,  flat,  disk-shaped  particles,  having  a  good 
deal  the  appearance  of  blood-corpuscles  (451),  for  which 
they  may  readily  be  mistaken ;  they  are,  however,  usually 
much  smaller. 

169.  Oxalate  of  lime  is  readily  soluble,  without  efferves- 
cence, in  dilute  nitric  and  hydrochloric  acids,  from  which 
it  is  again  thrown  down  in  the  form  of  a  white  precipitate, 
when  the  acid  solution  is  neutralized  with  ammonia  or 
potash. 

170.  It  is  insoluble  in  both  cold  and  hot  water;  also 
in  acetic  and  oxalic  acids;  and  in  solution  of  potash. 

171.  When   gently  ignited   before   the   blowpipe,    it 
undergoes  little  or  no  blackening,  and  becomes  converted 
into  carbonate  of  lime  (CaO,CO2),  which,  when  treated 
with  dilute  hydrochloric  or  nitric  acid,  dissolves  with 
effervescence  (399).     The  solution  thus  obtained  by  dis- 
solving the  carbonate  in  acid,  gives,  when  neutralized,  a 
white  precipitate  with  oxalate  of  ammonia,  but  none  with 
ammonia.     If  the  oxalate  be  kept  intensely  heated  for 
some  little  time  before  the  blowpipe,  the  carbonate  itself 
is  decomposed,  and  caustic  lime  is  formed  (402.) 

*  Dr.  Golding  Bird  imagined  that  the  dumb-bells  consisted,  not  of 
oxalate,  but  of  oxalurate  of  lime  (CaO,C6H,jN207).  (Urinary  Deposits, 
fourth  edition,  p.  219),  but  the  observation  that  oxalate-of-lime  cal- 
culi consist  often  of  aggregations  of  similar  dumb-bells  renders  such 
an  assumption  unnecessary. 


92  MORBID    URINE. 

SECTION  XVIII. 
Urine  containing  Cystine  (C6H6N04Sa). 

172.  Cystine  has  occasionally,  though  but  rarely,  been 
found  both  as  a  crystalline  deposit  in  urine,  and  also  in 

the  form  of  small  calculi;  in  one  of 
Fig.  27.  which  latter  it  was  first  discovered  by 

.  Dr.  Wollaston.     A  deposit  of  cystine, 

when  examined  under  the  microscope, 
usually  appears  as  a  mass  of  minute 
irregularly  formed  crystals,  having 
the  appearance  shown  in  Figure  27. 
To  the  naked  eye,  the  deposit  has  a 
good  deal  the  appearance  of  pale  fawn- 
colored  urate  of  ammonia  (93),  from 
which  it  may  be  readily  distinguished 
by  being  insoluble,  or  nearly  so,  in  warm  water,  and  con- 
sequently not  disappearing  when  the  urine  containing  it 
is  gently  warmed  (94). 

173.  One  of  the  most  characteristic  properties  of  cys- 
tine is  the  readiness  with  which  it  dissolves  in  ammonia. 
If  a  little  of  the  ammoniacal  solution,  thus  formed,  be 
allowed  to  evaporate  spontaneously  on  a  slip  of  glass,  the 
cystine  is  deposited  in  minute  hexagonal  crystals,  having 
the  form  and  appearance  shown  in  Fig.  28.     It  must  be 
remembered  that  occasionally  chloride  of  sodium  crys- 
tallizes in  octohedral  masses  (Fig.  29),  which  in  some 

Fig.  28.  Fig.  29. 

o 


o^a,         ^00° 

<i<Q,0 

o^o 

Cystine  Crystallized  from  Crystals  of  Chloride  of  So- 

au  Ammoiiiacal  solution.  dium,  resembling  Cystine. 

positions  may  have  at  first  sight  very  much  the  appear- 
ance of  cystine.     The  ready  solubility  of  the  chloride  in 


URINE    CONTAINING    CRYSTINE.  93 

water  is,  however,  sufficient  to  prevent  such  a  mistake. 
The  crystals  of  cystine,  too,  when  examined  with  polar- 
ized  light,  appear  beautifully  colored,  unless  very  thick, 
which  is  not  the  case  with  chloride  of  sodium.  The  tri- 
angular crystals  of  triple  phosphate  (44),  which  in  some 
positions  somewhat  resemble  cystine,  may  be  at  once 
distinguished  by  their  ready  solubility  in  dilute  acids 
(49, 174). 

174.  Cystine  is  insoluble  in  a  solution  of  carbonate  of 
ammonia,  but  soluble  in  the  fixed  alkaline  carbonates. 
It  is  very  sparingly  soluble  in  water,  even  when  warmed, 
and  insoluble,  or  nearly  so,  in  alcohol.     In  acetic  acid  it 
is  insoluble,  but  may  be  dissolved  in  nitric  and  hydro- 
chloric acids. 

175.  Urine  containing  cystine  has  usually  a  somewhat 
paler  color  than  the  healthy  secretion,  with  occasionally 
a  greenish  tint.     Its  specific  gravity  is  most  commonly 
rather   low.     It   may  generally  be  distinguished,  when 
fresh,  by  a  peculiar  and  slightly  aromatic  smell,  a  good 
deal  resembling  that  of  sweet  brier:  this  gradually  gives 
place  to  a  fetid,  disagreeable  odor,  owing  to  the  occur- 
rence of  putrefactive  decomposition. 

176.  Cystic  urine  is,  in  most  cases,  slightly  turbid  when 
passed,  and  becomes  considerably  more  so  as  it  cools,  the 
cystine  being  less  soluble  in  the  cold  .liquid.     A  small 
quantity  of  the  cystine,  however,  is  still  held  in  solution, 
and  may  be  precipitated  by  adding  a  little  acetic  acid  to 
the  filtered  urine. 

SECTION    XIX. 
Urine  containing  Iodine  and  other  foreign  matters. 

177.  When  the  compounds  of  iodine,  as  the  iodide  of 
potassium,  are  taken  internally,  it  is  generally  found  that 
nearly  the  whole  of  the  iodine  is  carried  off'  by  the  kid- 
neys, and  may  be  detected,  in  some  form  of  combination, 
in  the  urine.     It  may  readily  be  identified  by  adding  to 
the  secretion  a  drop  or  two  of  yellow  nitric  acid  or  very 
weak  chlorine  water,  and  then  testing  with  a  solution 
of  starch;  when,   if  iodine  is    present,  the    liquid   will 
assume  a  more  or  less  intense  purple  color  (807,  810). 


94  EXAMINATION    OF    MORBID    URINE. 

178.  Many  other  substances,   taken  into  the  system 
either  as  food  or  medicinally,  pass  into  the  urine  un- 
changed, and  may  frequently  be 'distinguished  by  their 
peculiar  properties.      This  is  especially  the  case   with 
many  of  the  vegetable  coloring  matters,  as  those  of  indi- 
go,* madder,  beetroot,  gamboge,  logwood,  &c.     Some  of 
these  may  occasionally  give  rise  to  the  suspicion  of  the 
presence  of  blood,  but  their  real  nature  may  generally  be 
ascertained  by  examination  under  the  microseope. 

179.  Besides  these  coloring  matters,  various  other  sub- 
stances, both  organic   and   inorganic,    are   occasionally 
found  in  urine.     Thus,  when  any  metallic  preparation 
has  been  taken  internally,  traces  of  the  metal,  in  some 
state  of  combination,  may  usually  be  found.     The  inor- 
ganic, and  some  of  the  organic  acids  also,  are  frequently 
to  be  detected ;  though,  when  neutral  salts  of  the  latter 
have  been  taken,  carbonates  of  the  bases  are  more  usually 
found.     In  addition  to  these,  fche  odorous  principles  of 
many  vegetables  appear  to  pass  off  unchanged  in  the 
urine,  where  they  may  often  be  recognized  by  their  pecu- 
liar smell. 


CHAPTER  V. 

EXAMINATION  OF  URINE  SUSPECTED  TO  CONTAIN  EITHER 
AN  UNNATURAL  PROPORTION  OF  SOME  ONE  OR  MORE 
OF  THE  USUAL  INGREDIENTS,  OR  ELSE  SOME  ABNORMAL 
MATTER. 

180.  IT  often  happens,  that,  owing  to  some  peculiarity 
of  color  and  appearance,  either  of  the  liquid  or  sedimen- 
tary portion  of  morbid  urine,  or  from  some  other  circum- 
stance, such  as  its  high  specific  gravity,  we  are  led  to 
form  some  conjecture  as  to  its  real  nature.  When  such 
is  the  case,  one  or  two  well-selected  experiments,  such  as 
those  about  to  be  described,  will  generally  be  found  suffi- 

*  A  deposit  of  indigo  has  been  found  in  the  urine  in  cases  in  which 
that  substance  had  not  been  taken  into  the  system. 


ESTIMATION    OF    UREA    IN    UKINE. 


95 


cicnt  to  decide  whether  or  not  the  suspected  peculiarity 
really  exists.  When,  however,  the  observer  is  unable  to 
form  a  tolerably  strong  opinion  as  to  the  nature  of  the 
urine  he  is  about  to  examine,  he  had  better  proceed  to 
test  it  according  to  the  directions  given  in  Chapter  VI. 

SECTION  I. 

Examination  of  Urine  suspected  to  contain  Urea  in  abnormal 

quantity. 

181.  When  the  presence  of  an  excess  of  urea  is  sus- 
pected, either  on  account  of  the  high  specific  gravity  of 
the  urine  (301),  or  from  any  other  cause,  a  drop  or  two 
of  the  liquid  should  be  placed  on  a  slip  of  glass,  and 
mixed  with  about  an  equal  quan- 
tity of  pure  colorless  nitric  acid.  Fig.  30. 
If  the  urea  is  present  in  large 
excess,  there  will  probably  be  a 
deposition  of  minute  rhomboidal 
crystals  of  the  nitrate  in  the  course 
of  a  few  minutes  (Fig.  30),  and  if 
no  trace  of  crystallization  is  visi- 
ble to  the  naked  eye,  the  mixture 
should  'be   examined  under  the 
microscope.    If  no  crystals  appear 
in  the  course  of  half  an  hour  or 
an  hour,  a  few  drops  of  the  urine 
may  be  slightly  concentrated  by 
evaporation  on  a  slip  of  glass,  at 
a   gentle  heat ;  and,   when   cool,              Nitrate  of  urea, 
mixed  as  before,  with  an  equal 

quantity  of  nitric  acid.  Crystals  of  the  nitra'te  will  now 
separate  if  any  considerable  quantity  of  urea  is  contained 
in  the  urine ;  and  from  the  rapidity  with  which  the  crys- 
tals form,  together  with  their  abundance,  the  student  will 
be  able,  after  a  little  practice,  to  form  a  tolerably  accu- 
rate opinion  as  to  the  relative  amount  of  urea  present  in 
the  urine.  If  a  microscope  is  not  at  hancj,  the  experiment 
may  be  made,  though  less  delicately,  without  it.  It 
must  be  remembered,  that  variations  in  the  atmospheric 
temperature  affect  the  crystallisation  of  this  salt  very 


96  ESTIMATION    OF    UREA 

materially;  in  cold  weather,  a  specimen  of  urine  will 
consequently  often  be  found  to  afford  an  abundant  crop 
of  crystals,  which,  in  warm  weather,  would  furnish  little 
or  none.  For  this  reason  it  is  often  advisable  to  cool  the 
mixture  artificially,  by  immersing  the  glass  containing  it, 
either  in  cold  water  or  a  freezing  mixture;  which  latter 
may  be  readily  made  by  mixing  a  little  pounded  nitrate 
of  ammonia  with  an  equal  weight  of  water.  The  nitric 
acid  may  very  conveniently  be  added  to  the  urine  in  a 
thin  watch-glass  in  which  it  has  been  previously  cooled 
by  floating  the  glass  upon  water.  Very  brilliant  leaf- 
lets of  the  nitrate  will  be  deposited  if  excess  of  urea  be 
present. 

Quantitative  Estimation  of  the  Urea. 

182.  Liebig's  Method. — This  is  founded  on  the  circum- 
stance that  urea  is  capable  of  combining  with  nitric  acid 
and  peroxide  of  mercury,  to  form  a  nearly  insoluble 
compound  (C2H4N2O2,N05,4HgO),  which  is  immediately 
precipitated  when  a  solution  of  urea  is  mixed  with  a 
solution  of  nitrate  of  mercury  containing  no  free  acid. 
But  since  this  reaction  does  not  take  place  with  the 
bichloride  of  mercury  which  is  formed,  by  double  decom- 
position, when  the  nitrate  of  mercury  is  added  to  urine 
containing  chloride  of  sodium,  it  is  necessary  to  remove 
the  chlorine  previously  to  determining  the  urea;  or  a 
larger  quantity  of  the  mercury-solution  would  be  em- 
ployed than  was  necessary  to  precipitate  the  urea.  The 
removal  of  the  chlorine  is  effected  by  means  of  nitrate  of 
silver,  its  quantity  having  been  previously  determined 
by  an  ingenious  application  of  the  principle  above  stated, 
that  nitrate  of  mercury  will  not  precipitate  urea,  in  the 
presence  of  common  salt,  until  a  sufficient  quantity  of 
the  mercury-salt  has  been  added  to  convert  all  the  chlo- 
ride of  sodium  into  nitrate  of  soda. 

The  test  solutions  required  for  this  purpose  are : — 

The  solution  of  nitrate  of  mercury,  No.  1,  for  deter- 
mining the  chlorine ; 

The  solution  of  nitrate  of  silver  for  removing  the  chlo'- 
rine; 


IN    UKINE.  97 

The  solution  of  nitrate  of  mercury,  No.  2,  for  deter- 
mining the  urcii. 

Preparation  of  the  solution  of  Nitrate  of  Mercury,  No.  1, 
employed  for  determining  the  Chlorine. — Pure  crystals  of 
protonitrate  of  mercury  are  dissolved  in  moderately 
strong  nitric  acid,  and  the  solution  heated  until  a  sample 
is  no  longer  rendered  turbid  by  chloride  of  sodium;  the 
solution  is  evaporated,  on  a  water-bath,  to  a  syrupy  con- 
sistence, and  diluted  with  about  10  times  its  bulk  of 
water ;  it  is  then  set  aside  for  twenty-four  hours,  and,  if 
necessary,  filtered.*  In  order  to  graduate  the  solution,  it  is 
requisite  to  prepare  a  saturated  solution  of  common  salt : 
pure  chloride  of  sodium  (colorless  rock  salt,  is  powdered, 
and  digested  with  water  (at  the  ordinary  temperature) 
for  twenty-four  hours,  with  occasional  shaking;  so  much 
salt  must  be  employed  that  a  considerable  quantity  may 
remain  undissolved.f  One  hundred  and  fifty  grain-mea- 
sures of  this  solution  (=47'76  grs.  of  chloride  of  sodium) 
are  poured  into  a  small  beaker,  and  mixed  with  45  grs. 
of  a  solution  of  urea  (containing  about  4  per  cent,  of 
urea),  and  with  75  grs.  of  a  cold  saturated  solution  of 
pure  sulphate  of  soda ;  to  this  mixture  the  solution  of 
nitrate  of  mercury  is  added,  from  a  burette,  with  con- 
stant stirring,  until  a  distinct  precipitate  is  permanently 
formed.;);  The  strength  of  the  mercury-solution  having 
been  thus  ascertained,  such  a  proportion  of  water  must 
be  added  to  it  that  100  grain-measures  may  correspond 
to  1  gr.  of  chloride  of  sodium. 

Preparation  of  the  solution  of  Nitrate  of  Silver  employed 

*  An  easier  process  for  the  preparation  of  this  solution  consists  in 
adding  finely  powdered  red  oxide  of  mercury  to  moderately  strong 
nitric  acid,  as  long  as  it  is  dissolved.  An  ounce  of  ordinary  nitric 
acid  (sp.  gr.  1-42)  will  dissolve  540  grs.  of  oxide  of  mercury,  and  may 
then  be  diluted  with  52  ounces  of  water. 

f  One  hundred  grain-measures  of  this  solution  contain  31 -84  grs.  of 
chloride  of  sodium. 

t  If  any  crystalline  precipitate  should  be  formed,  it  may  be  redis- 
solved  by  adding  a  little  water.  In  this  process  the  sulphate  of  soda 
is  added  for  two  reasons  ;  firstly,  because  the  compound  of  nitrate  of 
menmry  and  urea  is  less  soluble  in  saline  solutions  (as  urine  for  ex- 
ample) than  in  pure  water  ;  and,  secondly,  in  order  that  the  free  nitric 
acid  in  the  nitrate  of  mercury  may  be  neutralized  by  a  portion  of  the 
soda  from  the  sulphate,  which  is  thus  converted  into  bisulphate. 

9 


ESTIMATION    OF    UREA 


for  removing  the  Chlorine. — 174'36  grs.  of  fused  nitrate  of 
silver  are  dissolved  in  water,  and  diluted  till  the  solution 
amounts  to  6000  grain-measures ;  100  grain-measures  of 
this  solution  are  equal  to  one  grain  of  the  chloride. 

Preparation  of  the  solution  of  Nitrate  of  Mercury,  No.  2, 
employed  for  determining  the  U>ea. — A  solution  of  nitrate 
of  mercury  is  prepared,  according  to  the  directions  given 
above,  so  as  to  contain  about  25  grs.  of  nitrate  of  mer- 
cury in  180  grain-measures.  In  order  to  graduate  this 
solution,  20  grs.  of  pure  urea  are  dissolved  in  water,  and 
diluted  till  the  volume  of  the  solution  amounts  to  exactly 
1000  grs. ;  150  grain-measures  of  this  solution  are  poured 
into  a  beaker,  and  the  mercury-solution  is  added  from  a 
burette  till  a  few  drops  on  a  watch-glass  produce  a  dis- 
tinct yellow  color  with  carbonate  of  soda.  This  should 
be  the  case  after  the  addition  of  300  grain-measures  of 
the  mercury  solution,  but  if  the  latler  be  prepared  of  the 
above  strength,  less  than  that  quantity 
Fig.  31.  Fig.  32.  wiH  be  required,  and  so  much  water  must 
be  added  to  the  solution  as  will  bring  it 
to  the  proper  standard;  thus,  suppose 
only  296  grain- measures  had  been  used, 
then  to  every  296  grs.  of  the  solution,  4 
grs.  of  water  must  be  added ;  100  grs.  of 
this  solution  correspond  to  1  gr.  of  urea. 
For  the  expeditious  determination  of 
urea  in  urine,  the  analyst  should  be  pro- 
vided with  the  following  measures,  accu- 
rately graduated,  for  the  solutions  em- 
ployed:*— 

1.  A  pipette  (Fig.  31),  with  a  mark  upon 
the  tube  indicating  the  level  at  which 
225  grs.  of  distilled  water  would  stand. 
This  is  employed  for  measuring  the  urine 
after  precipitation  with  baryta. 

A  pipette.  A  Burette.        2.  A  burette  (Fig.  32),  capable  of  con- 
taining  100  grs.    of  distilled    water,  for 
the    mercurial    solution,    No.    1.     This   should  be   gra- 
duated as  accurately  as  possible. 


'*  These  may  \>e   obtained   from   Negretti  &    Zambra,   11,  Hatton 
Gardeu. 


IN    URINE.  99 

:"».  A  tall  narrow  glass  measure,  capable  of  containing 
1000  grs.  of  distilled  water. 

4.  A  graduated  burette,  containing  1000  grs.,  for  the 
mercurial  solution,  No.  2. 

Having  the  test  solutions  ready  prepared,  it  is 
necessary,  before  determining  the  urea  in  urine,  to  re- 
move the  phosphoric  acid,  which  is  effected  by  means 
of  a  mixture  of  2  vols.  of  cold  saturated  baryta-water, 
and  1  vol.  of  a  cold  saturated  solution  of  nitrate  of 
baryta.*  A  glass  cylinder,  of  about  1  oz.  capacity  is 
filled  to  overflowing  with  urine,  the  excess  being  made 
to  flow  off  by  covering  the  cylinder  with  a  glass  plate; 
two  such  cylinderfuls  are  poured  into  a  beaker,  and  mixed 
with  one  cylinderful  of  the  baryta-solution;  the  preci- 
pitate is  filtered  off,  and  the  amount  of  chloride  of  sodium 
contained  in  225  grain -measures  of  the  filtrate  (=150 
grs.  of  urine)  is  then  determined  by  slightly  acidulating 
with  nitric  acid,  and  adding  the  standard  solution  of 
mercury,  No.  1,  till  the  appearance  of  a  cloudiness ;  450 
grs.  more  of  the  filtrate  (=300  grs.  of  urine),  are  then 
measured  off;  acidulated  with  nitric  acid,  and  mixed  with 
a  quantity  of  the  standard  solution  of  silver  equal  to 
twice  that  of  the  mercury  solution  employed  in  the  pre- 
ceding experiment;  the  liquid  is  filtered,  and  half  the 
sum  of  the  mixed  liquors  is  taken  for  the  determination 
of  the  urea.  This  quantity  (  =  150  grs.  of  urine),  is 
poured  into  a  beaker,  and  the  graduated  mercurial  solu- 
tion, No.  2,  added  from  a  burette,  with  frequent  stirring, 
until  no  further  increase  of  the  precipitate  is  perceptible ; 
to  ascertain  if  sufficient  of  the  mercury  solution  has 
been  added,  a  few  drops  of  the  turbid  liquid  are  removed 
with  a  pipette  into  a  watch-glass,  and  a  few  drops  of  car- 
bonate of  soda  carefully  added  down  the  edge  of  the 
glass  ;f  if,  after  some  minutes,  the  mixture  retain  its 

*  The  former  to  neutralize  the  free  acid  of  the  urine,  the  latter  to 
decompose  the  alkaline  phosphates.  If  much  ammonia  be  present  in 
the  urine,  it  must  be  expelled  by  evaporation,  with  an  excess  of  baryta, 
on  the  water  bath,  as  it  would  interfere  with  the  determination  of  the 
urea. 

f  It  is  a  good  plan  to  place  a  row  of  drops  of  carbonate  of  soda  upon 
a  glass  plate,  and  to  add,  from  time  to  time,  a  drop  of  the  liquid  under 
examination,  until  it  begins  to  give  a  yellow  tinge. 


100  ESTIMATION    OF    UREA 

white  color,  a  further  quantity  of  the  mercury  solution 
is  to  be  added,  until  a  fresh  sample  exhibits  plainly  the 
yellow  color  after  the  addition  of  carbonate  of  soda. 
The  number  of  grains  employed  is  then  read  off,  and 
the  amount  of  urea  calculated,  100  grs.  of  the  mercurial 
solution  corresponding  to  one  grain  of  urea.* 

183.  The  absolute  quantity  of  urea  present  in  urine, 
may  also  be  roughly  ascertained  by  evaporating  1000 
grains  of  the  urine  to  dryness  on  a  water-bath,  in  a 
counterpoised  porcelain  dish,  and  treating  the  residue  in 
the  manner  described  in  paragraphs  52  to  56,  or  by  pre- 
cipitating the  concentrated  urine  (500  grs.)  with  nitric 
acid  (16),  and  weighing  the  nitrate  after  washing  with 
very  cold  water,  and  drying  at  212°. 

183a.  A  very  simple  method  of  determining  the  pro- 
portion of  urea  in  urine  consists  in  decomposing  it  by 
oxidation  with  a  solution  of  chloride  of  soda  (hypochlo- 
rite  of  soda),  and  measuring  the  nitrogen  evolved. 


C2H4N202+3(NaO,C10)=2C02-f4HO+3NaCl+N2. 

To  prepare  the  solution  of  hypochlorite  of  soda,  500 
grs.  of  good  chloride  of  lime  (bleaching  powder)  are 
stirred  with  boiling  water,  filtered,  and  the  residue  washed 
once  or  twice  with  the  boiling  water.  1000  grs.  of  crys- 
tallized carbonate  of  soda  are  dissolved  in  a  little  water 
and  added  to  the  solution,  which  is  then  filtered,  and 
made  up  to  20  oz.  with  water.  Before  determining  the 
urea  in  urine,  the  uric  acid  and  some  of  the  nitrogenized 
extractive  matters  must  be  precipitated  by  tribasic  acetate 
of  lead.  300  grain-measures  of  urine  are  mixed  with 

IP 

*  It  has  been  found  that,  in  analyses  of  urine,  when  the  amount  of 
urea  is  increasing,  an  error  is  committed,  tending  to  diminish  the  ap- 
parent amount  of  urea  ;  in  order  to  remove  this  error,  an  addition  has 
to  be  made — for  225  grain-measures  of  urine,  and  before  the  test  is 
applied — of  7'5  grs.  of  water  for  every  15  grs.  of  solution  of  mercury 
which  have  been  used  over  and  above  450  grain-measures,  in  a  pre- 
liminary determination.  To  obviate  an  error  in  the  opposite  direction, 
in  the  more  dilute  urines,  a  deduction  has  to  be  made  of  1-5  grain- 
measures  for  every  75  grs.  of  mercury  solution  used  less  than  450  grs. 


IN    URINE. 


101 


tribasic  acetate  of  lead  till  no  fresh  precipitate  is  ob- 
tained; the  solution  is  boiled  and  filtered,  the  precipitate 
being  washed  once  or  twice  with  water;*  the  nitrate  and 
washings  are  mixed  with  a  solution  of  50  grs.  of  car- 
bonate of  soda  in  a  little  water,  boiled,  and  again  filtered, 
the  precipitate  being  washed  as  before.  One  half  of  the 
cold  ftltrate  and  washings  is  introduced  into  a  flask  (ca- 
pable of  holding  from  five  to  six  ounces)  which  is  then 
rapidly  filled  up  to  the  brim  with  the  solution  of  chloride 
of  soda,  so  that  when  a  cork  is  inserted,  with  a  narrow 
bent  tube  for  collecting  the  gas,  the  tube  may  be  filled 
with  the  liquid,  to  the  exclusion  of  air.  The  flask  is 
then  placed  in  a  water-bath,  with  the  tube  dipping  beneath 
the  water  in  a  pneumatic  trough,  so  that  the  gas  may  be 
collected  in  a  tube  graduated  to  fractions  of  a  cubic  inch 
(Fig.  33).  Heat  is  then  applied  to  the  water-bath,  and 

Fig.  33. 


when  the  evolution  of  gas  begins  to  slacken,  the  flask 
itself  may  be  heated  with  a  spirit  lamp  until  the  volume 
of  the  gas  in  the  graduated  tube  exhibits  no  increase 

*  If  a  very  rapid  determination  be  required,  the  mixture  containing 
the  precipitate  may  be  measured  before  filtration,  and  half  that  measure 
taken  for  determining  the  urea,  so  that  the  washing  may  be  dispensed 
with. 

9* 


102  EXAMINATION    OF 

after  a  minute  or  two.  The  flask  is  then  removed,  the 
graduated  tube  sunk,  as  far  as  possible,  in  the  trough, 
and  when  the  temperature  has  fallen  to  60°  Fahr.,  the 
volume  of  the  nitrogen*  is  carefully  read  off,  being  cor- 
rected, by  calculation,  for  any  deviation  of  the  barometric 
pressure  from  thirty  inches.  1'549  cubic  inches  of  nitro- 
gen represent  1  gr.  of  urea.* 

If  ammonia  be  present  in  the  urine,  its  nitrogen  being 
evolved,  will  increase  the  apparent  amount  of  the  urea. 
After  the  experiment,  the  liquid  in  the  flask  should  be 
tested  with  a  little  sulphuric  acid,  to  ascertain  (from  the 
evolution  of  chlorine)  that  an  excess  of  chloride  of  soda 
was  present.*)* 

The  same  principle  may  be  more  easily,  though  less 
accurately,  applied  in  the  following  manner  (E.  Davy). 
A  measuring  tube  twelve  or  fourteen  inches  long  is  pro- 
vided, easily  closed  by  the  thumb,  and  graduated  to  tenths 
and  hundredths  of  a  cubic  inch.  This  tube  is  filled  rather 
more  than  one  third  full  of  mercury,  and  a  measured 
quantity  (50  or  60  grs.)  of  urine  poured  into  it.  The 
tube  is  then  quickly  filled  to  the  brim  with  solution  of 
chloride  of  soda,  closed  by  the  thumb,  and  inverted 
under  a  saturated  solution  of  common  salt  (which,  being 
heavier  than  the  solution  in  the  tube,  prevents  its  escape) 
contained  in  a  small  rnortar.  The  tube  is  allowed  to 
stand  for  three  or  four  hours,  or  until  the  volume  of  the 
nitrogen  ceases  to  increase,  and  the  amount  of  urea  is  then 
calculated  as  above.  In  this  process,  the  carbonic  acid 
is  retained  by  the  excess  of  chloride  of  soda  employed. 

184.  When  it  is  suspected  that  the  urea  is  present  in 
smaller  quantity  than  in  the  healthy  secretion,  or  is  even 
altogether  absent,  2000  grs.  of  the  urine  are  to  be  evapo- 
rated to  dryness  on  a  water  bath,  and  the  dry  residue 
well  stirred  with  successive  small  quantities  of  alcohol, 
which  will  dissolve  any  traces  of  urea  that  may  be  pre- 
sent. The  alcoholic  solution  is  then  to  be  evaporated  to 

*  The  carbonic  acid  having  been  retained  by  the  large  excess  of 
carbonate  of  soda  employed. 

f  This  method  of  estimating  urea  was  devised  by  Lecopte. 


MORBID    URINE.  103 

dryness  on  a  water-bath,  and  the  residue  which  it  leaves 
is  afterwards  treated  in  the  manner  described  in  para- 
graphs 341  and  842,  in  order  to  separate  the  whole  of  the 
urea,  which  may,  if  necessary,  be  weighed. 

SECTION  II. 

E. elimination  of  Urine  suspected  to  contain  Uric  (or  Litltlc) 
Acid  in  abnormal  quantity. 

185.  When  urine  is  suspected  to  contain  an  excess  of 
uric  acid,  it  may  be  examined  in  the  following  manner. 
Pour  off  the  clear  liquid  from  any  solid  deposit  that  may 
have  subsided  to  the  bottom,  and  retain  both  the  solid 
and  liquid  portions  for  examination. 

186.  A  little  of  the  sediment  is  placed  on  a  slip  of 
glass,  and  examined  under  the  microscope;  when,  if  uric 
acid  is  present  in  it,  either  alone,  or  mixed    with    the 
amorphous  or  rounded    particles  of  urate  of  ammonia 
(193),  or  other  matters,  it  may  be  distinguished  by  its 
peculiar  crystalline  forms,  most  of  the  modifications  of 
which  are  shown  in  the  annexed  figure  (Fig.  34). 

187.  If  the  sediment  consists  of  uric  acid,  it  will  prove 
insoluble  when  the  liquid  is  warmed.  If  urate  of  ammonia 
is  also  present,  however,  the  latter  will  readily  dissolve 
on  the  application  of  heat  (192),  leaving  the  crystalline 
uric  acid  unaffected. 

188.  Uric-acid  sediment  is  insoluble  in  dilute  hydro- 
chloric and  acetic  acids,  but  dissolves  readily  in  a  solution 
of  potash,  owing  to  the  formation  of  the  soluble  urate  of 
potash  (22). 

1S9.  When  uric  acid  is  moistened  with  a  little  tolerably 
strong  nitric  acid,  and  the  residue,  after  evaporation  at  a 
gentle  heat,  is  treated,  when  cold,  with  a  drop  or  two  of 
ammonia,  or  exposed  to  arnmoniacal  furnes,  a  beautiful 
purple  color  is  developed,  owing  to  the  formation  of 
muiexide  (23). 

190.  The  clear  urine,  separated  from  the  uric  acid 
sediment  (185),  being  still  saturated  with  the  acid,  the 
latter  may  be  gradually  precipitated  by  adding  a  few 


101 


EXAMINATION    OF 


Fig.  34. 


Crystalline  forms  of  Uric  Acid. 


drops  of  nitric  or  hydrochlo- 
ric acid.  The  uric  acid  thus 
precipitated  usually  has  the 
crystalline  forms  shown  in 
the  upper  and  middle  part 
of  the  figure. 

191.  When  a  deficiency 
of  uric  acid  is  suspected,  the 
best  way  of  ascertaining 
whether  or  not  such  is  the 
case,  is  to  filter  one  or  two 
thousand  grains  of  the  urine, 
in  order  to  separate  the 
mucus  and  any  other  solid 
matter  which  it  may  con 
tain,  and  which  may  be  se- 
parately examined  for  uric 
acid  under  the  <microscope 
(18G),  or  with  nitric  acid 
and  ammonia  (18H).  The 
filtered  urine  is  then  evapo- 
rated nearly  to  dryness,  on  a 
water-bath,  and  the  residue 
digested  with  dilute  hydro- 
chloric acid,  containing  one 
part  of  strong  acid  to  eight 
or  ten  of  water.  Any  uric 
acid  that  may  be  present 
will  thus  be  left  undissolved, 
and  may  be  examined  under 
the  microscope,orotherwise; 
and,  if  necessary,  weighed, 
after  being  first  dried  at  a 
temperature  of  212°  on  a 
water- bath. 


SECTION  III. 

Examination  of  Urine  suspected  to  contain  an  excess  of  Urate 
(or  Litliate)  of  Ammonia. 

192.  When  a  sediment  is  suspected  to  consist,  either 
wholly  or  partially,  of  urate  of  ammonia,  a  little  of  the 


MORIUI)    ITRTXtf.  10,r> 

urine  containing  it  is  to  be  warmed  over  a  spirit-lamp. 
If  it  consists  of  urate  of  ammonia  unmixed  with  other 
matters,  it  will  readily  dissolve  as  the  liquid  becomes 
warm,  and,  on  cooling,  will  be  again  precipitated.  When 
purpurine  is  present  (104),  the  urate  will  probably  not 
dissolve  quite  so  readily  on  the  application  of  heat  as 
when  it  is  unmixed  with  coloring  matter. 

193.  Under  the  microscope,  urate  of  ammonia  appears 
as  an  amorphous  powder,  frequently  interspersed    with 
minute  round  particles  larger  than  the  rest,  some  of  which 
are  occasionally  found  adhering  closely  together.     (See 
Fig.  11,  paragraph  91.)     More  rarely,  it  is  found  in  the 
form  of  large  masses,  containing  spiculae  (Fig.  12,  para- 
graph 92). 

194.  It   must  be  remembered  that   phosphate-of-lime 
sediment  usually  has  a  very  similar  appearance  under 
the  microscope  (108),  and  may  consequently  be  mistaken 
for  urate  of  ammonia,  if  the  micro- 

scopic appearance  alone   be  relied  Fig-  35. 

upon.      All    that   is  necessary,  in 

order  to  distinguish  between  them, 

is  to  add  a  drop  of  dilute  hydro- 

chloric acid  to  a  little  of  the  de- 

posit  on  a  slip  of  glass.     If  it  con- 

sists  of  phosphate  of  lime,  it  will 

instantly  dissolve   on  the  addition 

of  the  acid  (49,322)  ;  while,  if  urate 

of  ammonia,  it  will  be  acted  on  much  uric  Acid. 

more  slowly,  and  in  a  short  time  mi- 

nute crystals  of  uric  acid  (Fig.  35)  will  gradually  appear, 

having  been  displaced  from  the  urate  by  the  action  of 

the  hydrochloric  acid  (196). 


195.  When  uric  acid  coexists  in  a  sediment  with  urate 
of  ammonia,  which  is  of  very  common    occurrence,  it 
may  be  distinguished  under  the  microscope,  by  its  crys- 
talline forms  (186).     The  uric  acid  would  also  be  left  un- 
dissolved  when  the  liquid  is  warmed,  and   may  then,  if 
necessary,  be  separated  by  filtration,  and  further  examined. 

196.  Urate  of  ammonia  deposits  are  not  unfrequently 
found  mixed  with  the  earthy  phosphates,  especially  when 


106  EXAMINATION    OF 

the  urine  has  at  all  an  alkaline  reaction.  These  will  be 
left  undissolved  when  the  liquid  is  warmed,  and  may  be 
examined  under  the  microscope,  and  tested  with  dilute 
hydrochloric  acid  (317,  322). 

197.  When  albumen  is  present  in  urine  containing  a 
sediment  which  is  supposed  to  consist  of  urate  of  ammonia, 
it  may,  by  coagulating  when  heated,  disguise  the  solubility 
of  the  urate,  and  thus  lead  to  an  erroneous  opinion  as  to 
the  nature  of  the  deposit.  If,  however,  the  heat  be  applied 
very  gradually,  the  urate  of  ammonia  will  be  found  to 
dissolve  some  time  before  any  of  the  albumen  coagulates; 
so  that,  with  care,  this  source  of  error  may  be  avoided. 
Or  if  the  urine  has  been  inadvertently  allowed  to  boil, 
and  a  precipitation  of  albumen  has  taken  place,  the  liquid 
may  be  filtered,  while  hot,  and  the  clear  filtered  solution 
will,  on  cooling,  again   deposit  the  urate  of  ammonia ; 
which  may  then,  if  necessary,  be  further  examined  (94, 
192). 

198.  If  pus  or  mucus  be  contained  in  the  sediment, 
together  with  urate  of  ammonia,  the  urine  will  not  become 
perfectly  clear  on  the  application  of  heat ;  nor  will  those 
substances  dissolve  on  the  addition  of  dilute  hydrochloric 
acid.     They  may,  however,  be  distinguished  with  the  aid 
of  the  microscope  (328,  329). 

199.  When  it  is  required  to  estimate  the  quantity  of 
urate  of  ammonia  in  a  urinary  sediment,  a  portion  of  the 
latter,  derived  from  a  known  quantity  of  the  secretion,  is 
to  be  boiled  with  water,  and  filtered  while  hot ;   when  the 
soluble  urate  will  be  separated  from  any  uric  acid,  earthy 
phosphates,  &c.,  that  may  be  also  present  with  it.     The 
solution  is  then  concentrated  by  evaporation  at  a  gentle 
heat,  and  allowed  to  cool ;  when  the  urate  of  ammonia  will 
again  separate  in  the  solid  form,  and  after  drying  on  a 
water-bath,  may  be  weighed. 

SECTION  IV. 

Examination  of  Urine  suspected  to  contain  Urate  (or  Lithate) 

of  Soda. 

200.  When  gently  warmed,  the  deposit  dissolves,  like 
urate  of  ammonia,  and  reprecipitates  on  cooling. 


MORBID    URINE.  1()7 

201.  Under  the  microscope,  it  usually  appears  in  the 
form  of  small  circular,  and  sometimes  semi-crystalline 
grains,   covered   occasionally    with    irregularly    formed 
spiculae,  or  granular  protuberances,  as  shown  in  Fig.  13, 
paragraph  96. 

202.  When  ignited  before  the  blowpipe  on  platinum 
foil,  it  leaves  an  abundant  white  fusible  residue  of  car- 
bonate of  soda,  which  is  readily  soluble  in  water,  forming 
a  solution  which  is  strongly  alkaline  to  test-paper. 

203.  If  the  ignited  residue  be  treated,   on  a  slip  of 
glass,  with  a  drop  of  dilute  hydrochlo- 
ric acid,  it  dissolves  with  effervescence,  FiS-  36< 
forming  chloride  of  sodium  ;  which,  if         <jj^     O  a  -^ 
the  liquid  be  expelled  by  gentle  eva-            Qr  ^ 
poration,  is  gradually  deposited  in  mi-       Hf 

nute  cubical  cr37stals,  on  the  glass,  and 

may  be  easily  recognized  with  a  lens       ®       ^  iS 

or  a  microscope  (Fig.  36).  O    ^    ^   ^ 

204.  When  a  little  of  the  deposit,       ChloridQ  of Sodium> 
previous  to  ignition,  is  placed  in  a  drop 

of  nitric  acid  on  a  slip  of  glass,  and  the  residue,  after 
evaporation,  treated  with  a  little  ammonia,  in  the  manner 
described  in  paragraph  23,  a  purple  color  is  developed, 
similar  to  that  caused  under  the  same  circumstances,  with 
uric  acid  and  urate  of  ammonia. 

205.  Urate  of  soda  may  be  distinguished  from  urate  of 
ammonia,  which  in  chemical  properties  it  much  resem- 
bles, by  its  microscopic  appearance  (91,  96);  by  not  being 
entirely  dissipated  by  ignition  (202,  375) ;  by  giving  no 
ammoniacal  fumes  when  warmed  with  a  solution  of  pot- 
ash (377) ;   and  by  the  ignited  residue  yielding,  with 
hydrochloric  acid,  cubical  crystals  of  chloride  of  sodium, 
(203). 

SECTION  V. 

Examination  of  Urine  suspected  to  contain   an  excess  of 
Hippuric  Acid. 

206.  When  urine  is  suspected  to  contain  an  excess  of 
hippuric  acid,  an  ounce  or  so  of  the  liquid  is  evaporated 
on  a  water-bath  to  the  consistence  of  a  syrup ;  which  is 


108  EXAMINATION    OF 

then  mixed  with  about  half  its  bulk  of  strong  hydrochlo- 
ric acid. 

The  mixture  is  set  aside,  and  examined  after  the  lapse 
of  a  few  hours.  If  any  considerable  excess  of  hippuric 
acid  is  present,  it  will  gradually  crystallize  at  the  bottom 
of  the  dish,  in  fine  tufts  of  needle-like  crystals,  often 
colored  pink  by  the  admixture  of  purpurine,  and  having 
the  form  shown  at  a,  Fig.  37. 

Fig.  37. 


Hippuric  Acid. 

207.  If  the  acid  is  present  in  smaller  quantity,  there 
may  be  merely  a  few  detached  microscopic  needle-like  or 
branched  crystals,  deposited  here  and   there  upon  the 
glass,  as  shown  at  b  in  the  figure. 

208.  Hippuric  acid  is  readily  soluble  in  alcohol ;  the 
alcoholic  solution  leaving,  after  evaporation,  a  crystalline 
residue,  which  has   usually  the  appearance  shown  at  c, 
Fig.  37. 

209.  It  is  nearly  insoluble  in  cold  water,  but  readily 
soluble  in  hot.     On  cooling,  the  aqueous  solution  de- 
posits the  acid  in  well-defined  prismatic  crystals,  which 
are  either  detached,  as  in  d  (Fig.  37),  or  in  tufts,  as  shown 
at  a.     These  crystals  form  very  beautiful  objects  under 
the  microscope ;  and  when  examined  with  polarized  light, 
develop  colors  of  great  variety  and  brilliancy. 

SECTION  VI. 
Examination  of  Urine  suspected  to  contain  an  excess  of  Mucus. 

210.  Mucous  urine  always  deposits  a  viscid,  tenacious 
mass,  having  an  alkaline  reaction  (100),  and  consisting 


MORBID    URINE.  109 

chiefly  of  mucus,  often  mixed  with  the  earthy  phosphates, 
oxalate  of  lime,  and  other  matters.  If  the  urine  be 
shaken,  the  deposit  does  not  again  mix  uniformly  with 
the  liquid,  but  remains  cohering  in  ropy  masses,  which 
are  very  characteristic. 

211.  When,  owing  to  the  admixture  of  a  large  quan- 
tity of  earthy  phosphates,  the  deposit  has  no  longer  the 
property  of  cohering  together,  the  microscope  must  be 
resorted  to,  in  order  to  determine  whether  or  not  much 
mucus  is  present ;  the  appearance  and  abundance  of  the 
peculiar  granular   corpuscles   (315,    328),   furnishing   a 
rough  index  of  the  quantity  present. 

212.  It  is  possible  that  pus  may  also  be  present,  in 
which  case,  unless  in  very  small  quantity,  it  may  gene- 
rally be  detected  in  the  manner  described  further  on  (247, 
258),  where  will  be  found  the  means  of  distinguishing 
between  pus  and  mucus. 

213.  If  it  is  wished  to  determine  the  amount  of  mucus 
contained  in  a  deposit,  in  which  it  is  mixed  with  earthy 
phosphates,  urates,  &c.,  the  sediment  must  be  filtered,  and 
washed  with  a  little  boiling  water,  in  order  to  dissolve 
out  the  urates;  it  may  then  be  treated  with  a  little  very 
dilute  hydrochloric  acid,   which  will   dissolve  out  the 
earthy  phosphates,  when  the  residue  of  mucus  may,  after 
careful  washing  and  drying  on  a  water-bath  or  in  a  hot- 
water  oven,  be  weighed. 

SECTION  VII. 

Examination  of  Urine  suspected  to  contain  an  abnormal 
proportion  of  Extractive  Matter. 

214.  It  is  often  of  some  importance  to  be  able  to  iden- 
tify the  presence  of  an  excess  of  the  peculiar  yellow 
coloring  matter,  of  which  the  bulk  of  the  extractive  mat- 
ter of  urine  appears  to  consist;  and  also  that  of  purpurine, 
which  is  probably  a  morbid  modification  of  the  yellow 
substance. 

Yellow  Coloring  Matter. 

215.  An  excess  of  the  yellow  coloring  matter  may  be 
recognized  by  boiling  a  little  of  the  suspected  urine,  and 

10 


110  EXAMINATION    OF 

then  adding  to  it  a  few  drops  of  hydrochloric  acid.  A 
more  or  less  intense  red  color  is  in  this  way  produced ; 
the  intensity  of  the  color  indicating  the  comparative 
amount  of  the  yellow  coloring  matter  present.  In  healthy 
urine,  a  faint  lilac  or  pinkish  tint  only  is  caused  by  the 
hydrochloric  acid ;  while,  if  the  coloring  matter  is  in 
large  excess,  an  exceedingly  intense  crimson  is  produced. 

Purpurine. 

216.  The  presence  of  purpurine,  or  the  red  coloring 
matter  so  often  met  with  in  cases  even  of  very  slight  de- 
rangement of  the  system,  is  easily  ascertained.     Owing 
to  its  solubility  in  water  or  urine,  it  is  never  met  with  as 
a  deposit  per  se. 

217.  Purpurine,  however,  has  a  remarkable  tendency 
to  unite  with  urate  of  ammonia  (104),  and  whenever  a 
deposit  of  that  substance  is  formed  in  urine  containing 
purpurine,  the  latter  is  invariably  precipitated  with  it, 
giving  the  sediment,  which  would  otherwise  be  white,  or 
nearly  so,  a  more  or  less  decided  pink  or  red  color. 
When  purpurine  is  present  in  a  deposit  of  urate  of  am- 
monia, the  latter  is  not  so  easily  soluble  in  hot  water, 
so  that  the  red  deposit  does  not  disappear  so  readily  on 
the  application  of  heat,  as  when  no  purpurine  is  present 
(94.) 

218.  If  a  deposit  of  urates,  colored  with  purpurine,  be 
digested  in  warm  dilute  alcohol,  the  purpurine  will  dis- 
solve, leaving  the  deposit  nearly  colorless,  and  forming  a 
solution  of  a  yellowish-pink  color. 

219.  Urine  containing  purpurine,  when  no  excess  of 
urates  is  present,  has  a  more  or  less  decided  pink  or  red 
color,  which  may  appear  at  first  sight  very  similar  to 
blood. 

220.  Purpurine  may  be  distinguished  from  blood,  when 
present  in  a  sediment,  by  microscopic  examination,  when 
the  true  nature  of  the  uric  deposit  will  be  at  once  appa- 
rent (318,  323),  together  with  the  absence  of  blood  disks 
(330).     When  treated  with  warm  alcohol  also,  the  color- 
ing matter  will  be  dissolved  out  (218). 

221.  Purpurine,  when  contained  in  solution  .in  urine, 
may  be  precipitated  by  adding  a  little  warm  aqueous 


MORBID    URINE.  Ill 

solution  of  uratc  of  ammonia,  which  will,  on  cooling, 
separate  from  the  liquid,  carrying  with  it  nearly  the 
whole  of  the  coloring  matter,  forming  a  pink  deposit,  and 
leaving  the  urine  nearly  colorless  (217). 

SECTION  VIII. 

Examination  of  Urine  suspected  to  contain  an  abnormal 
proportion  of  Fixed  Alkaline  Salts. 

222.  When  an  excess  or  deficiency  of  any  of  the  fixed 
alkaline  salts  is  suspected  to  be  present,  a  known  weight 
of  the  urine  may  be  taken,  from  which  the  proportion  of 
the  substance  in  question  is  estimated  in  the  manner  de- 
scribed in  Chapter  II.,  paragraphs  66  to  84. 

SECTION  IX. 

Examination  of  Urine  suspected  to  contain  an  abnormal  pro- 
portion of  Earthy  Phosphates. 

223.  If  the  suspected  urine  is  neutral  or  alkaline  to 
test-paper,  a  sediment  of  earthy  phosphates  may  be  pre- 
cipitated even  in  cases  where  they  do  not  exist  in  larger 
proportion  than  in  the  healthy  secretion  ;  so  that  the 
mere  occurrence  of  a   small  phosphatic  deposit  is   not 
necessarily  a  proof  of  their  excess  (107). 

224.  On  warming  the  urine,  the  sediment,  if  phosphatic, 
remains  undissolved  (94,  229).* 

225.  The  earthy  phosphates  are  readily  soluble  in  most 
of  the  dilute  acids,  especially  hydrochloric,  nitric,  and 
acetic. 

226.  If  the  acid  solution  thus  formed  be  neutralized 
or  supersaturated  with  ammonia,  the  earthy  phosphates 
are  immediately  reprecipitated  (496). 

227.  They  are  quite  insoluble  in  potash,  ammonia,  and 
the  alkaline  carbonates  (49c). 

227a.  When  collected  on  a  filter,  washed  with  water, 
and  moistened  with  nitrate  of  silver,  the  earthy  phos- 
phates assume  a  bright  yellow  color. 

*  If  the  urine  contains  albumen,  the  deposit  must  be  filtered  off  and 
washed  before  being  tested. 


112  EXAMINATION    OF 

228.  A  deposit  of  earthy  phosphates  may  generally  be 

immediately  recognized  under  the 
Fig.  38.  microscope.  The  crystalline  forms 

of  the  triple  magnesian  phosphate 
have  been  already  noticed  (44),  and 
these  are  often  mixed  with  the 
amorphous  phosphate  of  lime  (Fig. 
38).  If  a  drop  of  dilute  hydro- 
chloric or  acetic  acid  be  added, 
while  the  sediment  is  in  the  field 
of  the  microscope,  the  crystals  will 
Mixed  Phosphates.  be  seen  rapidly  to  dissolve,  leaving 

the  liquid  clear,  unless  uric  acid  or 

some  other  matter  insoluble  in  the  acid  be  also  present 

in  the  deposit. 

229.  When  urine,  containing  in  solution  an  excess  of 
earthy  phosphates,  is  boiled,  a  portion  of  them  is  usually 
precipitated,  giving  the  liquid  a  turbid  appearance,  re- 
sembling the  coagulation  of  a  small  trace  of  albumen 
under  similar"circumstances  (49,  139).    It  may  readily  be 
distinguished  from  albumen,  by  adding  a  drop  or  two 
of  dilute  nitric  or  hydrochloric  acid,  which  will  immedi- 
ately redissolve  the  precipitate,  if  it  consists  of  phosphates, 
but  if  albuminous,  will  not  affect  it.     When  the  precipi- 
tate is  found  to  dissolve  on  the  addition  of  the  first  drops 
of  acid,  it  is  advisable,  before  concluding  that  albumen 
is  not  present,  to  acidify  the  mixture  more  strongly,  since 
the  coagulum  of  albumen,  when  very  small  in  quantity, 
occasionally  dissolves  on  the  first  application  of  acid,  but 
is  wholly  reprecipitated  on  the  addition  of  a  few  drops 
more  of  the  acid  (140—143). 

230.  If  the  absence  or  a  deficiency  of  the  earthy  phos- 
phates is  suspected,  the  urine  may  be  treated  with  a  slight 
excess  of  ammonia,  when,  if  no  precipitate  occurs,  it  may 
be  inferred  that  they  are  either  altogether  absent  or  else 
present  in  very  small  quantity. 

231.  In  order  to  ascertain,  in  such  a  case,  whether  or 
not  any  traces  of  them  are  present,  a  pint  or  two  of  the 
urine  may  be  evaporated  to   dryness,  and   the  residue, 
after  incineration,  digested  with  dilute  hydrochloric  acid, 
which  will  dissolve  out  the  earthy  salts,  if  any  are  present. 


MORBID    URINE.  113 

The  acid  solution  thus  obtained  is  then  filtered,  and 
supersaturated  with  ammonia,  when,  if  any  earthy  phos- 
phates are  present,  they  will  be  thrown  down  in  the  form 
of  a  white  precipitate  (496). 

Quantitative  determination  of  the  Earthy  Phosphates. 

232.  When  it  is  required  to  estimate  the  proportion  of 
earthy  phosphates  in  a  deposit  containing  uric  acid  and 
other  matters,  a  portion  of  the  sediment,  derived  from  a 
known   quantity  of  urine,  is  first  washed  with  a  dilute 
solution   of  ammonia,    and    then   digested    with    dilute 
hydrochloric  acid,  until  the  latter  ceases  to  dissolve  any- 
thing further.     The  acid  solution  of  the  earthy  salts,  thus 
obtained,  is  separated  from  the  insoluble  matter  by  filtra- 
tion, and  then  supersaturated  with  ammonia,  which  will 
throw  down  the  whole  of  the  earthy  phosphates.     The 
mixture,  after  standing  a  short  time,  to  allow  the  magne- 
sian  phosphate  wholly  to  separate,  is  to  be  filtered ;  and 
the  precipitate,  after  drying  at  a  gentle  heat,  is  to  be 
weighed,  when  its  weight  will  represent  the  amount  of 
deposited  earthy  phosphates  in  the  quantity  of  urine  from 
which  it  was  derived. 

SECTION  X. 
Examination  of  Urine  suspected  to  contain  Sugar. 

233.  When  urine  is  suspected  to  contain  sugar,  it  may 
be  examined  by  paragraphs  122  to  130.     If  any  white 
scum  or  sediment  is  present,  it  should  also  be  examined 
for  the  torula  vesicles,  under  the  microscope  (132). 

234.  The  method  of  estimating  the  quantity  of  sugar 
contained  in  diabetic  urine  will  be  fully  described   in 
Chapter  VII. 

SECTION  XI. 
Examination  of  Urine  suspected  to  contain  Albumen. 

235.  A  little  of  the  suspected  urine  is  to  be  gently 
boiled  in  a  test  tube.     If  any  albumen  is  present,  it  will 
be  coagulated,  forming  a    more  or  less   copious   white 
deposit  in  the  liquid.     The  precautions  necessary  for  the 

10* 


114  EXAMINATION    OF 

success  of  this  experiment  have  been  already  noticed  in 
paragraphs  139  to  143. 

236.  To  another  portion  of  the  urine  add  a  few  drops 
of  nitric  acid,  observing  the  precautions  mentioned  in 
paragraph   143.     If  a  precipitate  or  milkiness  be  pro- 
duced by  the  acid,  and  also  by  boiling  (235),  the  presence 
of  albumen  in  the  urine  may  be  considered  certain  (141). 

237.  The   proportion    of   albumen   in    urine   may  be 
estimated  with  tolerable  accuracy  by  boiling  a  known 
quantity  of  the  secretion,  and  separating  the  coagulum 
by  filtration;  the  insoluble  matter  is  then  washed  with  a 
little  dilute  nitric  or  hydrochloric  acid,  in  order  to  dis- 
solve out  any  earthy  phosphates  that  may  have  been 
precipitated  (140),  dried  on  a  chloride  of  calcium  bath, 
at  a  temperature  of  240°  or  250°,  and  weighed. 

238.  If  the  quantity  of  albumen  is  so  small  as  not  to 
form  a  tolerably  decided  coagulum  when  boiled,  but  only 
to  render  the  liquid  opalescent,  it  will  be  hardly  necessary 
to  proceed  with  the  quantitative  determination. 

239.  The  method  of  making  a  complete  quantitative 
analysis  of  albuminous  urine  will  be  fully  described  in 
Chapter  VIII. 

SECTION  XII. 
Examination  of  Urine  suspected  to  contain  Blood. 

240.  When,  from  its  peculiar  red  or  brown  color,  or 
from  other  circumstances,  the  presence  of  blood  is  sus- 
pected  in    urine,  it    may  first  be   examined   under  the 
microscope  for  any  blood-corpuscles   that  may  be  con- 
tained in  it  (146).     If  no  coagula  have  separated  (145), 
the  liquid  should  be  allowed  to  repose  for  a  short  time, 
in  order  to  let  the  corpuscles  subside  to  the  bottom ;  and 
a  drop  then  taken  from  the  bottom  of  the  vessel  will 
generally  be  found  to  contain  an  abundance  of  the  cor- 
puscles, more  or  less  modified  in  form  and  appearance 
(456). 

241.  When  so  much  blood  is  present  as   to  give  the 
urine  a  decidedly  red  color,  it  will  probably  be  unnecessary 
to  wait  for  the  subsidence  of  the  corpuscles;  and  a  drop 


MORBID    URINE.  115 

of  the  liquid  taken  indiscriminately  will  usually  be  found 
to  contain  sufficient  for  microscopic  examination. 

242.  If  the  blood  has  coagulated,  either  in  the  bladder 
or  subsequent  to  emission,  it  is  most  probable  that  the 
greater  portion  of  the  blood-corpuscles  will  have  been 
entangled  in  the  coagula,  and  may  be  forced  out  by  gentle 
pressure   under  a  strip   of  thin  glass,  so  as  to  be  made 
visible  with  the  help  of  the  microscope. 

243.  The  urine  should  also  be  tested  for  albumen  by 
heat  and   nitric  acid,  in  the  manner  already  described 
(139 — 143).     The  coagulated  albumen  will  probably,  in 
this  case,  be  more  or  less  highly  colored,  owing  to  the 
presence  of  the  coloring  matter  of  the  blood  (147,  455). 
If  the    urine   already  contains  coagula,  or  other  solid 
matter,  it  should  be  separated  from  them  by  filtration, 
before  being  tested  for  albumen ;  as  their  presence  would 
tend  to  mask  the  appearance  of  coagulation. 

244.  If  the  urine  contains  much  blood,  it  may  probably 
become  spontaneously  gelatinous,  owing  to  the  coagula- 
tion  of  the  dissolved  fibrin  (145,  448).     This  coagulum 
should  be  examined  under  the  microscope,  since  a  some- 
what similar  gelatinous  character   might  be  occasioned 
by  the  presence  of  a  considerable  quantity  of  mucus  (101); 
or,  if  the   urine   be   alkaline,  of  pus  (251,  680).     The 
coagulum    of  fibrin,  when    pressed    between    glasses,  is 
usually  found   to   be  composed   of  minute   amorphous 
particles,  with  a  few  red  blood-corpuscles;  quite  different 
in  character  from  the  granular  mucus-corpuscles  (146, 328). 

245.  Urine  containing  bile  or  purpurine  (148, 104),  has 
sometimes  nearly  the  same  color  and  appearance  as  when 
blood  is  present,  and  may,  without  care,  be  inadvertently 
mistaken  for  it.     If  no  trace  of  blood-corpuscles  can  be 
detected  under  the  microscope,  we  should,  before  deciding 
that  blood  is  present,  prove  that  the  color  of  the  secretion 
is  not  due  to  purpurine,  or  biliary  mattei^  by  applying 
the  tests  described  for  the  detection  of  those  substances, 
in  paragraphs  219—221,  246,  &c. 


116  EXAMINATION    OF 

SECTION  XIII. 
Examination  of  Urine  suspected  to  contain  Biliary  Matter. 

246.  When  urine  is  suspected  to  contain  biliary  matter, 
it  may  be  examined  by  Pettenkofer's  and  Heller's  tests, 
described  in  paragraphs  149  and  151.     If  these  fail  to 
afford  indications  of  it  in  the  urine,  the  latter  should  be 
concentrated  by  evaporation  on    a  water-bath,  and  the 
strong  aqueous  or  alcoholic  solution  of  the  evaporated 
residue  again  tested  (150). 

SECTION  XIV. 
Examination  of  Urine  suspected  to  contain  Pas. 

247.  When  pus  is  contained  in  urine,  unmixed  with 
any  considerable  quantity  of  mucus;  it  may.  readily  be 
distinguished  under  the  microscope  by  its  containing  the 
peculiar  nucleated  pus-granules  (153,  678).     These  parti- 
cles, when  the  urine  is  allowed  to   stand  a  short  time, 
gradually  subside  to  the  bottom  of  the  liquid  :  and  when 
shaken,  again    mix    readily  with   the    urine,    in    which 
respect  a  deposit  of  pus  differs  essentially  from  one  of 
mucus ;   the  latter  forming,  on  agitation,  tenacious  ropy 
masses,  which  do  not   again   mix    uniformly    with    the 
liquid  (99). 

248.  As  purulent  deposits  frequently  appear  to  the 
naked  eye  very  similar  to  those  of  the  earthy  phosphates, 
(106),  and  as  it  is  often  difficult  to  distinguish  between 
pus  and  mucus  when  they  coexist  in  a  specimen  of  urine, 
I  will  mention  the  more  characteristic  tests   by  which 
purulent  deposits  may  be  most  readily  identified. 

249.  It  must  be  remembered  that  the  form  and  general 
appearance  of  the   pus-and-mucus  corpuscles   vary  con- 
siderably under  different  pathological  conditions  of  the 
patient ;    so  tfmt  it  is  not   unfrequently   impossible   to 
distinguish  beBreen  them.     The  granules  of  pus  appear 
indeed,  to  be  identical  with  those  of  mucus  ;  the  difference 
between  the  two  substances  being  in  the  composition  of 
the  fluid  in  which  the  particles  float  (661,  676). 

250.  Under  the  microscope,  with  a  power  of  about  400 


MORBID    URINE.  117 

diameters,     the     pus-granules  Fig-  39- 

have  the  appearance  repre- 
sented at  a,  Figure  39 ;  and  on 
the  addition  of  a  little  dilute 
acetic  acid,  they  become  much 
more  transparent,  and  in  each 
corpuscle  one  or  more  internal 
nuclei  are  rendered  visible, 
having  the  appearance  shown 
at  6  in  the  figure.  The  granules  of  pus  will  be  found  to 
float  about  freely  in  the  liquid  (678,  156). 

251.  When  the  urine  is  alkaline,  the  character  of  the 
pus  contained  in  it  is  different;    being  then  thick  and 
gelatinous,  closely  resembling  mucus  (680). 

252.  The  granules  of  mucus  present  almost  precisely 
the  same  appearance  under  the  microscope  as  those  of 
pus,  but  are  usually,  perhaps,  rather  smaller,  and  less 
distinctly  granular  on  the  surface.  The  addition  of  dilute 
acetic  acid^renders  visible  the  interior  nuclei,  as  in  the 
case  of  pus  (250).     The  acid,  however,  coagulates  the 
fluid  portion  of  the  mucus,  owing,  probably,  to  the  pre- 
cipitation of  the  mucin,  before  held  in  solution  by  a  small 
quantity  of  alkali  (663).     In  the  case  of  urine  containing 
only  a  small  quantity  of  mucus,  it  is  uncertain  whether 
this  phenomenon  of  coagulation  will  be  seen,  on  account 
of  the  dilution  of  the  mucous  fluid,  and  also  because  the 
coagulation  may  have  been  already  occasioned  by  the 
presence  of  the  large  quantity  of  water  (663).     When, 
however,  the  quantity  of  mucus  is  tolerably  abundant, 
the  coagulation  by  acetic  acid  furnishes  a  very  character- 
istic reaction. 

253.  The  earthy  phosphates,  which  to  the  naked  eye 
closely  resemble  pus,  may  be  at  once  distinguished  under 
the  microscope  by  their  crystalline  form  (43),  and  also 
by  being  readily  soluble  on  the  addition  of  dilute  acetic 
acid  (228). 

254.  The  liquor  puris,  in  which  the  pus-granules  float, 
always  contains  albumen  in  solution  (676).    This  may  be 
readily  detected   by  the  tests    of  heat  and  nitric  acid, 
already  described  (139) ;  unless,  indeed,  the  quantity  of 


118  EXAMINATION    OF 

urine  is  so  large,  compared  with  that  of  the  pus  contained 
in  it,  as  to  have  rendered  it  too  dilute. 

255.  The  fluid  portion  of  mucus,  on  the  contrary,  con- 
tains no  albumen,  or  merely  a  minute  trace  (663),  and 
consequently    when   diluted    with    urine    undergoes    no 
coagulation  when  heated,  or  tested  with  nitric  acid.     It 
is,  however,  very  possible  that  urine  containing  an  excess 
of  mucus,  and  no  pus,  may  also  contain  albumen  ;   so 
that  the  mere  presence  of  albumen  in  the  secretion  is  not 
necessarily  a  proof  of  the  presence  of  pus  (101). 

256.  A  certain  quantity  of  fatty  matter,  readily  soluble 
in  ether,  is  always  present  in  pus  (676,  678),  but  seldom, 
and  in  much  smaller  proportion,  in  mucus   (663).      If, 
therefore,  the  deposit,  or  the  residue  after  evaporation,  be 
boiled  with  a  little  ether,  and  the  ethereal  solution  thus 
obtained  is  found  to  yield,  on  evaporation,  small  globules 
of  yellowish  fat,  it  is  probable  that  pus  is  present. 

257.  A  deposit  of  pus,  when  treated  with  a  solution  of 
ammonia  and  potash,  becomes  converted   in^o  a  thick 
gelatinous  mass,  often  sufficiently  tenacious  to  allow  the 
tube  containing   it  to  be  inverted   without  any  of  the. 
mixture  flowing  out.    This  reaction  is  very  characteristic. 

258.  Urine  containing  pus  is  most  commonly  either 
neutral   or    slightly   acid,   and   becomes   alkaline   very 
slowly.     Mucous  urine,  on  the  contrary,  even  if  acid, 
when  it  is  passed,  quickly  becomes  ammoniacal,  and  alka- 
line to  test-paper  (100).     Tubercular  matter  deposited  in 
the  urine  might  at  first  be  mistaken  for  pus ;    a  minute 
examination,    however,  will   show  debris  of  cells,    and 
sometimes  crystals  of  cholesterin. 

SECTION  XV. 

Examination  of  Urine  suspected  to  contain  Fat  or  Chylous 
Matter. 

259.  Urine  suspected  to  contain  fat,  may  be  examined 
with  a  tolerably  high  power  under  the  microscope,  when 
it  is  occasionally  found  to  contain  minute  oil-globules 
(158,  325).     This,  however,  is  not  always  the  case ;   so 
that  the  best  way  of  proving  the  presence  of  fatty  matter, 
is  to  agitate  a  little  of  the  suspected  urine  with  about  half 


MORBID    URINE.  119 

its  bulk  of  ether ;  which  will  separate  the  fat  from  the 
watery  fluid,  forming,  usually,  a  yellowish  solution,  which 
gradually  rises  to  the  surface.  The  ethereal  solution 
thus  obtained  may  then  be  cautiously  evaporated  on  a 
water-bath,  when  the  fat  or  oily  matter  will,  if  present, 
be  left  behind ;  and  may,  if  necessary,  be  tested  as  to  its 
oily  nature,  by  shaking  up  with  hot  water;  when,  if  oil 
or  fat,  it  will  break  up  into  minute  globules,  immiscible 
with  the  water  (158). 

260.  Chylous  urine  is  usually  so  peculiar  in  appearance 
that  it  can  hardly  be  mistaken  for  any  other  morbid  con- 
dition of  the  secretion.  Under  the  microscope,  it  appears 
to  be  chiefly  composed  of  amorphous  albuminous  matter 
in  a  minute  state  of  division,  mixed  occasionally  with 
globules  resembling  those  found  in  the  lymph  and  chyle. 
On  agitation  with  ether,  it  will  yield  abundant  traces  of 
fatty  matter,  and  distinct  oily  globules  may  occasionally 
be  distinguished. 

261.  This  form  of  urine  always  contains  albumen  in 
solution.     A  portion  of  this,  or  more  probably  a  little 
soluble  fibrin  (145),  not   unfrequently  coagulates  spon- 
taneously after  emission,  giving  the  urine  a  gelatinous  or 
semi  solid  consistence.     The  presence  of  albumen  may 
be  shown  by  applying  to  the  urine,  rendered  clear  by 
filtration,  the  tests  of  heat  and  nitric  acid  (235). 

262.  If  it  is  required  to  ascertain  the  quantity  of  fatty 
matter  in  any  specimen  of  urine,  a  known  weight  of  the 
secretion  may  be  agitated  with  successive  small  quantities 
of  ether ;    and  the  ethereal  solution  thus  obtained  will 
leave,  after  evaporation,  the  fatty  matter  which  it  had 
dissolved.     This  is  to  be  dried  on  a  water-bath  until  it 
ceases  to  lose  weight. 

SECTION  XVI. 
Examination  of  Urine  suspected  to  contain  Semen. 

263.  Microscopic  examination  is  the  only  trustworthy 
means  of  determining  whether  or  not  any  traces  of  semen 
are  contained  in  urine.  The  urine  should  be  well  shaken, 
and  then  left  to  stand  a  short  time,  in  order  to  allow  the 
flocculi  of  mucus  and  spermatozoa  to  subside.  The  greater 


120  EXAMINATION    OF 

part  of  the  fluid  is  then  poured  off,  and  a  drop  containing 
the  sediment,  taken  from  the  bottom,  and  examined  under 
the  microscope,  with  a  magnifying  power  of  at  least  four 
or  five  hundred  diameters.  If  semen  is  present,  the  sper- 
matozoa always  contained  in  that  secretion  will  then  be 
visible  (160),  together,  probably,  with  the  peculiar  semi- 
nal granules  also  found  in  the  spermatic  fluid  (161). 

264.  Traces  of  albumen,  also,  may  generally  be  detected 
in  seminal  urine,  by  the  application  of  heat  and  nitric  acid 
(235). 

SECTION  XVII. 
Examination  of  Urine  suspected  to  contain  Oxalate  of  Lime. 

265.  When  the  presence  of  oxalate  of  lime  is  suspected, 
the  urine  should  be  allowed  to  stand  some  little  time,  in 
order  that  the  sediment  may  partially  subside.     A  little 
of  the  liquid  taken  from  the  bottom  of  the  vessel  is  then 
treated  in  the  manner  described  in  paragraph  164,  and 
examined  under  the  microscope ;  when,  if  present,  the 
oxalate  will  be  seen  in  the  form  of  octohedral  crystals 
(166,  168),  or  of  the  dumb-bell  shape. 

266.  Oxalate  of  lime  is  insoluble  in  acetic  acid,  but 
dissolves  without  effervescence   in    dilute   hydrochloric 
acid,  and  is  again  precipitated  unchanged,  when  the  acid 
solution  is  neutralized  or  supersaturated  with  ammonia 
or  potash. 

267.  If  the  oxalate  of  lime  deposit  be  gently  ignited, 
and  the  residue  after  ignition  treated  with  dilute  hydro- 
chloric acid,  it  will  be  found  to  dissolve  with  effervescence, 
having  been  converted,  during  ignition,  into  the  carbonate 
of.  lime  (399). 

268.  When  it  is  required  to  estimate  the  amount  of 
oxalate  of  lime  sediment,  it  may,  if  unmixed  with  other 
deposits,  be  separated  by  filtration  from  a  known  quantity 
of  urine,  and  weighed.     When  mixed  with  earthy  phos- 
phates   or  urates,  the   deposit,  after  filtration,  may  be 
washed  with  a  little  dilute  acetic  acid  to  dissolve  out  the 
phosphates  (49&);  the  mixture  is  then  filtered,  and  the 
insoluble  portion  digested  in  dilute   hydrochloric  acid, 
which  will  dissolve  the  oxalate  of  lime,  leaving  undissolved 


MORBID    URINE.  121 

any  uric  acid  that  may  be  present.  The  acid  solution  is 
then  filtered,  if  necessary,  and  supersaturated  with  am- 
monia; by  which  the  oxalate  will  be  again  precipitated. 
It  may  then  be  collected  on  a  weighed  filter,  dried  on  a 
water-bath,  and  weighed. 

SECTION  XVIII. 
Examination  of  Urine  suspected  to  contain  Cystine.* 

269.  The  presence  of  cystine  may  generally  be  identi- 
fied by  means  of  the  microscope  (172),  especially  after 
the  deposit  has  been  dissolved  in  ammonia,  and  allowed 
to  crystallize,  either  spontaneously  or  with  the  aid  of  a 
very  gentle  heat,  from  the  ammoniacal  solution  (270). 

270.  Treat  a  portion  of  the  suspected  deposit  with  a 
little  solution  of  ammonia;    if  it  is  cystine,  it   will  be 
found  readily  to  dissolve.    Place  a  drop  of  the  ammoniacal 
liquid  on  a  strip  of  glass,  and  allow  it  to  evaporate  spon- 
taneously.    The  peculiar  hexagonal  tabular  crystals  of 
cystine  thus  obtained,  are  very  characteristic  (173). 

271.  Neutralize  the  rest  of  the  ammoniacal  solution 
formed  in  270,  with  acetic  acid ;  the  cystine,  if  present, 
will  be  precipitated  (174). 

272.  Cystiae  may  be  distinguished  from  urate  of  am- 
monia,   which   it   often   closely    resembles   in   external 
appearance,  by  being  insoluble,  or  nearly  so,  when  the 
urine  containing  it  is  warmed  ;  while  urate  of  ammonia 
readily  dissolves  (172,  94). 

273.  It  may  be  distinguished  from  the  earthy  phos- 
phates by  its   insolubility  in   acetic   acid   (174);    by  its 
appearance  under  the  microscope  (317,  320) ;  and  also  by 
its  ready  solubility  in  ammonia  (173).     From  chloride 
of  sodium,  cystine  may  be  distinguished  by  its  sparing 
solubility  in  water  (173). 

274.  If  cystine  be  boiled  with  a  little  caustic  potash, 
and  the  solution  tested    with    acetate   of  lead,  a   black 
precipitate  of  sulphide   of  lead   will   be   produced;   in 

*  In  cases  where  cystine  has  been  excreted,  it  has  generally  been 
found  to  be  most  abundant  in  the  morning  urine. 
11 


122  EXAMINATION    OF 

consequence  of  the  large  amount  of  sulphur  contained 
in  the  cystine  ( 


SECTION  XIX. 

Examination  of  Urine  suspected  to  contain  other  Foreign  Matters 
not  included  in  the  foregoing  sections. 

275.  When  the  presence  of  any  other  kind  of  foreign 
matter  is  suspected  in  the  urine  (180),  such  as  metallic 
salts,  iodine,  inorganic  or  organic  acids,  &c.,  a  few  tests, 
such  as  hydrosulphuric  acid,  hydrosulphate  of  ammonia, 
&c.,  will  generally  lead  to  their  detection  without  much 
difficulty.  (See  Parts  IY  and  Y  ;  also  my  '  Introduction  to 
Practical  Chemistry,  '  Parts  II  and  III.)  If  the  suspected 
substance  is  organic,  either  the  urine  itself  or  the  evapo- 
rated residue  may  be  tested;  but  when  a  non-  volatile 
inorganic  substance  is  to  be  looked  for,  it  is  generally 
advisable  to  incinerate  the  evaporated  residue,  and  test 
the  ash  for  the  substance  in  question. 


CHAPTER  YL 

EXAMINATION  OF   MORBID  URINE,  THE  NATURE  OF  WHICH 
IS  ALTOGETHER   UNKNOWN. 

276.  WHEN  a  specimen  of  urine  is  suspected  to  differ 
in  some  respect  from  the  healthy  secretion,  it  will  gene- 
rally be  found  easy,  by  means  of  a  very  few  simple  expe- 
riments, such  as  those  which  I  am  about  to  describe,  not 
only  to  ascertain  whether  or  not  such  is  the  case,  but 
also  to  discover  the  nature  of  the  particular  morbid  con- 
dition in  question ;  whether  it  be  that  one  or  more  of  the 
normal  constituents  of  healthy  urine  is  present  in  an 

*  According  to  Stadeler,  tyrosine  (C18HUN06)  has  been  found  in  the 
form  of  a  sediment  in  urine,  in  extreme  derangement  of  the  liver.  It 
dissolves  in  boiling  water,  and  is  deposited  in  fibrous  crystals  on  cool- 
ing. Its  solution  gives  a  red  flocculent  precipitate  with  pernitrate  of 
mercury. 


MORBID    URINK. 


123 


abnormal  proportion,  or  whether  it  be  due  to  the  presence 
of  some  substance  which  is  never  found  in  the  healthy 
secretion.  In  such  an  examination,  the  microscope  will 
be  found  to  afford  most  valuable  and  ready  assistance, 
the  simple  microscopic  inspection  of  a  deposit  often  ren- 
dering its  true  nature  at  once  apparent.  Whenever, 
therefore,  the  student  has  access  to  one,  he  will  do  well 
to  avail  himself  of  it  as  much  as  possible ;  and  he  will 
soon  find  that,  with  a  little  experience,  he  will  be  able 
readily  to  di'scriminate  between  the  more  common  forms 
of  urinary  deposits. 

For  the  method  of  distinguishing  the  several  forms  of 
deposit  under  the  microscope,  see  paragraphs  315  to  332. 

SECTION  I. 
Examination  of  Urine  containing  some  solid  Deposit. 

277.  The  urine  may  be  first  tested  with  blue  litmus 
paper,  which  should  be  allowed  to  remain  for  some  time  in 
the  urine;  if  acid,  the  color  will  change  to 

red,  or  reddish  purple.  Should  the  blue 
color  remain  unchanged,  test  it  with 
yellow  turmeric  or  reddened  litmus  pa- 
per; if  the  urine  is  alkaline — owing,  pro- 
bably, to  the  conversion  of  urea  into  car- 
bonate of  ammonia  (11) — the  turmeric  will 
become  brown,  and  the  reddened  litmus 
blue;  while,  if  the  color  in  both  cases 
remain  unaltered,  the  urine  may  be  con- 
sidered neutral. 

278.  The  specific  gravity  of  the  urine 
may  then  be  taken. 

279.  This  is  most  readily  done  by  means 
of  the  urinometer,  which  is  a  little  instru- 
ment constructed  on  the  principle  of  the 
hydrometer,  the  usual  form  of   which  is 

shown  in  the  annexed  figure.  The  tube,  when  used,  is 
simply  immersed  in  the  urine  at  the  temperature  of  60° 
Fahr. ;  and  when  it  has  come  to  rest,  the  number  on  the 
graduated  scale,  which  stands  at  the  level  of  the  liquid, 
when  added  to  1000,  will  represent  the  specific  gravity 


Fig.  40. 


124  EXAMINATION    OF 

of  the  fluid.  For  example,  if  the  level  of  the  liquid 
stands  at  5  on  the  scale,  the  specific  gravity  of  the  urine 
will  be  1005 ;  if  at  30,  it  will  be  1030,  and  so  on  (301). 

280.  If  a  urinometer  is  not  at  hand,  the  specific  gravity 
of  the  urine  may  be  taken  by  means  of  a  bottle,  or  even 
with  a  small  piece  of  glass.*54" 

281.  The  deposit  may  now  be  for  the  most  part  sepa- 
rated from  the  urine,  by  allowing  it  to  subside  for  a 
short  time  in  a  tall  glass,  and  then  pouring  off  the  clear 
liquid,  or  drawing  it  off  with  a  syphon  or  pipette.     The 
portion  of  urine  containing  the  sediment  in  suspension 
may  be  first  examined.     For  the  mode  of  examining  the 
clear  liquid  separated  from  it,  see  paragraphs  300  to  314. 

Examination  of  the  Solid  Deposit. 

282.  If,  owing  to  some  characteristic  peculiarity  in  the 
appearance  of  the  deposit,  or  of  the  urine  containing  it, 
or  from  other  circumstances,  the  observer  has  reason  to 
suspect  the  nature  of  the  sediment,  he  may  at  once  pro- 
ceed to  apply  the  tests  for  the  suspected  substance,  accord- 
ing to  the  directions  given  in  Chapter  Y.     At  first,  how- 
ever, and  until  he  has  had  some  little  experience  on  the 
subject,  he  will  do  well  to  adopt  some  such  method  of 
examination  as  the  following. 

283.  In  the  great  majority  of  cases,  the  deposits  con- 
tained in  urine  will  be  found  to  consist  of  one  or  other 
of  the  following  substances — viz.,  earthy  phosphates,  uric 
acid,  urate  of  soda  or  ammonia,  or  oxalate  of  lime  ;  some- 
times alone,  sometimes  two  or  more  mixed  with  each 
other,  or  with  mucus  or  other  matters.     The  first  experi- 
ments, therefore,  should  be  directed  to  the  detection  of 
these  four  substances. 

284.  Put  a  little  of  the  urine  containing  the  deposit 
into  a  test  tube,  and  warm  it  gently  over  a  lamp.     IF  IT 
READILY  DISSOLVES,  it  is  probably  URATE  OF  SODA  OR 
AMMONIA  (192,  200);  in  which  case  one  or  two  of  the 
more  characteristic  tests  for  those   substances  may  be 
applied,  and  the  deposit  may  be  examined   under  the 

*  See  Introduction  to  Practical  Chemistry,  fourth  edition,  p.  56. 


MORBID    URINE.  125 

microscope,  in  order  to  confirm  or  correct  the  first  result. 
If  purpurine  is  present  with  the  unite,  which  may  be 
known  by  its  pink  or  reddish  color,  the  deposit  will  pro- 
bably not  dissolve  so  immediately  on  warming,  as  when 
the  coloring  matter  is  absent  (192).  If  the  deposit  does 
not  dissolve  when  gently  warmed,  nor  yet  when  heated 
nearly  to  boiling,  it  must  be  further  tested  as  follows. 

285.  IF    THE     DEPOSIT     DOES    NOT     DISSOLVE    WHEN 

WAKMKD,  add  to  a  few  drops  of  the  sedimentary  urine  in  a 
test  tube,  a  little  acetic  acid. 

286.  IF   THE    DEPOSIT    DISSOLVES    IN    ACETIC   ACID,    it 

probably  consists  of  EARTHY  PHOSPHATES;  the 'nature  of 
which,  whether  consisting  of  phosphate  of  lime,  or  triple 
phosphate,  or  a  mixture  of  both,  may  be  distinguished 
by  submitting  a  little  of  the  deposit  to  microscopic  ex- 
amination (228,  317,  322).  (Confirm  47,  225—227). 

287.  IF   THE    DEPOSIT    PROVES    INSOLUBLE    IN    ACETIC 

ACID,  test  another  portion  with  a  little  dilute  hydrochlo- 
ric acid.  If  it  DISSOLVES  IN  THE  ACID,  and  the  acid  solu- 
tion thus  obtained  gives,  when  neutralized  with  ammonia, 
a  white  precipitate,  it  is  probably  OXALATE  OF  LIME  (266). 
(Confirm  319,  267.) 

288.  IF   THE    HYDROCHLORIC  ACID   FAILS   TO  DISSOLVE 

THE  BEPOSIT,  it  may  be  tested  for  URIC  ACID  by  means  of 
nitric  acid  and  ammonia,  in  the  manner  described  in  para- 
graph 23.  Uric  acid  may  also  be  readily  distinguished 
under  the  microscope  (318).  (Confirm  187,  188.) 

289.  If  the  deposit  proves  to  consist  neither  of  earthy 
phosphates,  uric  acid,  urate  of  ammonia,  nor  oxalate  of 
lime,  it  must  be  examined  for  the  other  matters  which 
are  occasionally,  though  less  frequently,  met  with  in  mor- 
bid urine,  and  which  have  been  already  noticed  in  Chap- 
ters IV  and  V.     It  must  be  remembered  that,  in  perhaps 
the  majority  of  cases,  urinary  deposits  do  not  consist 
exclusively  of  any  one  substance,  but  contain  two  or  more 
mixed  together;  as  when  the  earthy  phosphates  occur 
associated  with  an  excess  of  mucus.     The  action  of  the 
several  tests  may  frequently  in  this  way  be  more  or  less 
masked,  and  when  taken  alone,  may  lead  to  erroneous 
conclusions.    In  such  cases,  the  microscope  will  be  found 


126  EXAMINATION    OF 

of  infinite  value,  and  should  always,  when  available,  be 
employed  (315). 

290.  If  the  deposit  sinks  readily  to  the  bottom  of  the 
vessel,  forming  a  PALE   GREENISH  YELLOW  SEDIMENT, 
which,  on  agitation,  is  again  diffused  readily  and  uni- 
formly in  the  liquid,  it  probably  consists  of  PUS  (247). 
(Confirm  250,  254,  256,  257,  156.) 

291.  If,  on  the  other  hand,  the  deposit  is  TENACIOUS 
AND  ROPY,  not  mixing  uniformly  with  the  liquid  when 
shaken,  it  probably  contains  an  excess  of  MUCUS  (210). 
(Confirm  211,  100,  156.) 

292.  If  the  deposit  is  DARK  COLORED,  brown,  or  red, 
and  has  been  found  not  to  consist  of  urate  of  ammonia 
colored  with  purpurine  (284),  it  probably  contains  BLOOD; 
in  which  case  the  clear  portion  of  the  urine  (281)  will 
give  indications  of  albumen  when  heated,  or  when  tested 
with  nitric  acid  (243).     (Confirm  240,  242,  245.) 

293.  When  the  deposit  is  WHITE  OR  NEARLY  so,  having 
proved  insoluble  when  warmed    (284),   and   also  when 
treated  with  dilute  hydrochloric  and  acetic  acids  (285, 
286);  and  is  found  to  be  readily  SOLUBLE  IN  A  SOLUTION 
OF  AMMONIA,  the  ammoniacal  solution  yielding  on  evapo- 
ration   HEXAGONAL   CRYSTALLINE   PLATES,  it  is  probably 

CYSTINE  (272,  270,  273). 

294.  If  the  deposit  is  PALE  YELLOW,  tolerably  soluble 
when  warmed  (200),  but  does  not  appear  to  consist  of 
urate  of   ammonia,  owing  to  its  yielding  no  ammonia 
when  warmed  with  a  solution  of  potash  (205),  and  ap- 
pearing under  the  microscope,  not  as  an  amorphous  sedi- 
ment, but  in  small  irregularly  shaped  roundish  or  oval 
particles,  with  or  without  projecting  protuberances  (324), 
it  is  probably  URATE  of  SODA.     (Confirm  202,  203,  204.) 

295.  If,  when  a  little  of  the  urine  is  agitated  with  a 
little  ether  in  a  test-tube,  and  the  ethereal  solution,  after 
separating  from  the  watery  portion  on  which  it  floats,  is 
found  to  leave,  after  evaporation  at  a  gentle  heat,  a  resi- 
due of  fat  or  oily  matter,  the  presence  of  FAT  may  be 
inferred  (259).     (Confirm  325.) 

296.  If  the  urine  is  OPAQUE  AND  ALMOST  MILKY  in 
appearance,  yielding  traces  of  fat   when    treated  with 
ether;  and  is  found,  when  examined  under  the  micro- 


MORBID    URINE.  127 

scope,  to  contain  an  abundant  white  amorphous  or. granu- 
lar deposit  of  albumen  or  fibrin,  together  probably  with 
small  round  colorless  corpuscles,  it  probably  contains 
CHYLOUS  MATTER  (260).  (Confirm  261,  326.) 

297.  If,  on  examination  under  a  microscope  of  high 
magnifying  power,  minute  ANIMALCULES  are  visible,  hav- 
ing the  appearance  shown  in  Figure  23,  page  60,  it  is 
probable  that  SEMEN  is  present  (160).    (Confirm  161, 
264.)* 

298.  The  following  table  may  serve  to  facilitate  the 
examination  of  deposits  with  reagents.    It  must,  however, 
be  borne  in  mind,  that  until  the  observer  has  had  some 
little  experience  in  the  action  of  the  several  tests,  he  must 
not  depend  too  much  on  the  result  of  any  one  experi- 
ment; but  must,  in  all  cases,  confirm  his  suspicions  by 
one  or  more  corroborative  tests. 


TABLE 

For  facilitating  the  Examination  of  Urinary  Deposits  by  means  of 
Chemical  Tests. 

299.  Test  first  for  the  earthy  phosphates,  uric  acid, 
u rates  of  soda  and  ammonia,  and  oxalate  of  lime  (283). 

1.  THE  SEDIMENT  DISSOLVES  WHEN  WARMED  ;    Urate  of 

soda  or  ammonia  (200,  284).    NOT  SOLUBLE  WHEN 
WARMED  ;  See  2. 

2.  SOLUBLE  IN  ACETIC  ACID  ;  Earthy  phosphates  (286). 

INSOLUBLE  IN  ACETIC  ACID  ;  See  3. 

3.  SOLUBLE  IN  DILUTE  HYDROCHLORIC  ACID  ;  Oxalate 

of  lime  (287).    INSOLUBLE  IN  DILUTE  HYDROCHLO- 
RIC ACID  ;  See  4. 

4.  PURPLE  WITH  NITRIC  ACID  AND  AMMONIA;  Uric  acid 

(288). 

*  Specimens  of  urine  are  occasionally  met  with,  holding  in  suspen- 
sion a  deposit  (either  amorphous  or  crystalline)  which  is  insoluble  in 
acids  and  alkalies  as  well  as  in  alcohol  and  ether ;  but  since  it  is  at 
least  diminished  by  shaking  with  hydrochloric  acid  and  ether,  it  ap- 
pears to  consist  of  an  earthy  salt  of  one  of  the  fatty  acids. 


128  EXAMINATION    OF 

If  the  deposit  prove?  to  be  neither  of  the  above,  it  is 
probably  one  of  <fche  following  : — 

5.  GREENISH  YELLOW  DEPOSIT,  EASILY  DIFFUSED  ON 

AGITATION;  Pus?  (290). 

6.  EOPY  AND  TENACIOUS  ;    Mucus  ?  (291). 

7.  RED  OR  BROWN;  NOT  SOLUBLE  WHEN  WARMED;  THE 

FLUID  PORTION  COAGULABLE  BY  HEAT  AND  NITRIC 
ACID;  Blood?  (292). 

8.  SOLUBLE  IN  AMMONIA  ;  THE  SOLUTION  LEAVING,  ON 

EVAPORATION,    HEXAGONAL    CRYSTALS ;     Cystine  ? 

(293). 

9.  ETHER  YIELDS,  AFTER  AGITATION,  AN  OILY  OR  FATTY 

RESIDUE  ;  Fatty  matter  (295). 

10.  MILKY  APPEARANCE:  Chylous  matter  (296). 

SECTION  II. 

Examination  of  Urine  containing  no  Solid  Deposit  ;  or  from 
which  a  Deposit  has  been  separated  (281). 

300.  Test  the  urine  with  litmus  and  turmeric  paper 
(277).*    If  ALKALINE,  it  must  be  tested  for  ALBUMEN 
with  nitric  acid  (305,  306). 

301.  Take  the  specific  gravity  (279).f    If  the  SPECIFIC 
GRAVITY  is  HIGHER  THAN  1025,  the  urine  may  perhaps 
be  found  to  contain  either  SUGAR  or  an  EXCESS  OF  UREA 
(302,  304).     If  the  specific  gravity  is  not  higher  than 
1025,  pass  on  to  305.     See  also  304. 

302.  Whether  UREA  be  present  in  excess,  may  be  ascer- 
tained by  mixing  a  little  of  the  urine  in  a  watch-glass, 
with  an  equal  bulk  of  pure  nitric  acid,  keeping  the  glass 
cool  by  allowing  it  to  float  in  cold  water.     If  any  excess 
of  urea  is  present,  a  more  or  less  abundant  crop  of  crys- 

*  If  these  experiments  had  been  already  made  before  the  separa- 
tion of  the  sedimentary  and  non-sedimentary  portions  of  the  urine 
(281),  they  need  not  be  repeated.  When  the  alkalinity  is  due  to 
ammonia  or  carbonate  of  ammonia,  red  litmus  paper,  which  has  been 
rendered  blue  by  it,  will  regain  its  color  when  dried  by  a  gentle  heat. 

f  See  above  note. 


MORBID    URINE.  129 

tals  of  nitrate  of  urea  will,  in  a  short  time,  appear  in  the 
mixture  (181).  (Confirm  183.) 

303.  When  a  microscope  is  at  hand,  we  can  in  this 
manner  detect  even  a  very  slight  excess  of  urea.  A  drop 
of  the  suspected  urine  is  placed  on  a  slip  of  glass,  and 
mixed  with  a  drop  of  pure  nitric  acid.  If  even  a  small 
excess  of  urea  is  present,  minute  crystals  of  the  nitrate 
may  generally  be  seen,  after  a  short  time,  with  a  very 
moderate  magnifying  power. 

304:.  To  prove  the  presence  of  SUGAR,  a  little  of  the 
urine  may  be  examined  by  paragraphs  122  and  126. 
(Confirm  113.)  It  must  here  be  borne  in  mind,  that  very 
decided  traces  of  sugar  may  exist  in  urine  without  raising 
the  density  to  a  suspicious  extent,  so  that  the  mere  cir- 
cumstance of  the  specific  gravity  of  the  urine  being  below 
1025  is  no  proof  whatever  of  the  absence  of  sugar ;  and 
in  any  doubtful  case  it  should  be  carefully  looked  for  by 
means  of  the  tests  above  referred  to. 

305.  Boil  a  little  of  the  urine  in  a  test-tube.     If  the 
liquid  remains  clear,  pass  on  to  307 ;  but  if  a  PRECIPITATE 
is  PRODUCED,  it  may  be  owing  to  the  presence  either  of 
albumen  (235),  or  of  an  excess  of  earthy  phosphates  (109). 
To  distinguish  between  them,  add  to  the  boiled  portion 
a  few  drops  of  nitric  acid.    If  the  PRECIPITATE  DISSOLVES, 
and  is  not  reprecipitated  by  the  addition  of  a  few  more 
drops  of  the  acid,  it  probably  consists  of  EARTHY  PHOS- 
PHATES (229)  (confirm  228,  226) ;  while,  if  it  either  does 
not  dissolve,  or  after  being  dissolved  by  the  first  drop  or 
two  of  the  acid,  again  precipitates  when  the  liquid  is 
more   strongly   acidified,   ALBUMEN   is   indicated   (143). 
(Confirm  137,  138.) 

306.  It  must  be  remembered  that  when  the  urine  is 
alkaline  ALBUMEN  may  be  present  in  it  without  being 
coagulated  by  boiling  (142).     Such  urine  should  there- 
fore be  tested  for  albumen  by  means  of  nitric  acid  (141). 

307.  Add  to  a  little  of  the  suspected  urine  a  few  drops 
of  nitric  acid.     If  a  PRECIPITATE  is  PRODUCED,  either 
immediately  or  after  a  short  time,  none  having  been 
occasioned  by  boiling  (305),  an  EXCESS  OF  URIC  ACID  is 
probably  present  (190).    (Confirm  23,  288.)   If  the  urine 
is  alkaline,  the  precipitate  thus  occasioned  may  consist  of 


130  EXAMINATION    OF 

ALBUMEN,  since  that  substance  would  not  then  be  pre- 
cipitated by  boiling  (306). 

308.  Evaporate  a  little  of  the  urine  on  a  water-bath,  to 
the  consistence  of  a  syrup,  and  add  about  half  its  bulk  of 
strong  hydrochloric  acid.     If,  after  the  lapse  of  a  few 
hours,  tufts  or  branches  of  NEEDLE-SHAPED  CRYSTALS  are 
visible,  either  to  the  naked  eye  or  when  examined  under 
the  microscope,  an  excess  of  HIPPURIC  ACID  is  probably 
present  (206).     (Confirm  208,  209.) 

309.  If  THE  URINE  is  HIGHLY  COLORED,  it  is  probable, 
either  that  it  contains  an  excess  of  yellow  coloring  mat- 
ter, or  that  blood,  biliary  matter,  or  purpurine  is  present.* 
To  determine  which  of  these  it  is — 

310.  Boil  a  little  of  the  urine ;  if  it  contains  BLOOD,  the 
albumen  will  COAGULATE,  mixed  with  some  of  the  color- 
ing matter  (243).     (Confirm  240,  245.) 

311.  If  an  excess  of  YELLOW  COLORING  MATTER  is  pre- 
sent, the  boiled  urine,  when  mixed  with  a  little  hydro- 
chloric acid,  will  assume  a  more  or  less  decided  RED  COLOR 
(215). 

312.  The  presence  of  biliary  matter  may  be  proved  by 
Pettenkofer's  and  Heller's  tests  (149,  151).  (Confirm  152.) 

313.  If  PURPURINE  is  present  in  solution,  the  urine 
usually  has  a  more  or  less  decided  pink  color;  and  when 
a  little  warm  aqueous  solution  of  urate  of  ammonia  is 
mixed  with  it,  that  salt  precipitates  as  the  liquid  cools, 
and  carries  with  it  nearly  the  whole  of  the  purpurine, 
which  gives  the  precipitate  a  PINK  COLOR.  (221).     (Con- 
firm 218,  220.) 

314.  The  following  table  may  be  found  useful  for  refer- 
ence (298). 

*  It  will  be  remembered  that  many  vegetable  coloring  matters  taken 
into  the  stomach  make  their  appearance  in  the  urine,  and  might,  by 
a  careless  examination,  be  mistaken  for  blood,  &c. 


MORBID   URINE.  131 

TABLE 

For  facilittitituj  the  Examination  of  the  clear  liquid  portion  of  Urine,  by 
means  of  Tests. 

1.  SPECIFIC  GRAVITY  HIGHER  THAN  1025 ;  See  2  and  3. 

2.  CRYSTALS  WITH  NITRIC  ACID  ;  Excess  of  urea  (302). 

3.  HEAT  WITH  SULPHATE  OF  COPPER  AND  POTASH  ;  Su- 

gar (304). 

4.  IF  NEUTRAL   OR  FEEBLY  ACID  TO   TEST-PAPER,  See  5, 

&c.    IF  ALKALINE,  see  7. 

5.  PRECIPITATE  FORMED  ON  BOILING;  SOLUBLE  IN  NI- 

TRIC ACID;  Excess  of  earthy  phosphates  (305). 

6.  PRECIPITATE  FORMED  ON  BOILING;  INSOLUBLE  IN 

NITRIC  ACID;  Albumen  (305). 

7.  PRECIPITATE  FORMED  BY  NITRIC  ACID  ;  Excess  of  uric 

acid  or  albumen  (307). 

8.  CONCENTRATED  URINE  YIELDS  NEEDLE-SHAPED  CRYS- 

TALS WITH  HYDROCHLORIC  ACID;    Hippuric  acid 
(308). 

9.  IF  THE   URINE   IS  HIGHLY   COLORED,  see   10,    11,    12, 

and  13. 

10.  DARK  COAGULUM  FORMED  ON  BOILING;  Blood?  (310). 

11.  BED  COLOR  WITH  HYDROCHLORIC  ACID;  Excess  of 

coloring  matter  (311). 

12.  PlNK  PRECIPITATE  WITH  WARM  SOLUTION  OF   URATE 

OF  AMMONIA  ;  Purpurine  (313). 

13.  CHANGE  OF  COLOR  WITH  NITRIC  ACID,  &cv;  Biliary 

matter  (152,  312). 

SECTION  III. 
Microscopic  Examination  of  Urinary  Deposits  (276,  289). 

315.  Place  a  drop  of  the  urine  containing  the  deposit — 
after  being  allowed  to  stand  a  short  time,  that  the  sedi- 
ment may  subside — on  a  strip  of  glass ;  cover  it  with  a 


132  MICROSCOPIC    EXAMINATION 

small  square  of  thin  glass,*  and  examine  it  with  a  mag- 
nifying power  of  about  two  hundred  diameters.  Observe 
whether  the  particles  are  CRYSTALLINE,  AMORPHOUS,  or 
ORGANIZED.  If  CRYSTALLINE,  refer  to  paragraph  316  ;  if 
AMORPHOUS,  to  paragraph  321;  and  if  ORGANIZED,  pass  on 
to  paragraph  327.  When,  as  is  frequently  the  case,  the 
deposit  appears  to  consist  of  a  mixture  of  two  or  more 
different  forms  of  matter,  each  of  these  should  in  succes- 
sion be  examined,  until  the  nature  of  the  whole  of  the 
deposit  is  clearly  understood. 

316.  IF  THE  DEPOSIT  is  CRYSTALLINE,  it  is  probably 
either  URIC  ACID,  TRIPLE  PHOSPHATE,  or  OXALATE  OF 
LIME  ;  or  possibly  CYSTINE. 

317.  If  the  crystals  are  STELLATE  (Fig.  41),  or  TRIAN- 
GULAR PRISMS  (Fig.  42),  instantly  disappearing  on  the 
addition  of  acetic  acid,  they  consist  of  the  TRIPLE  PHOS- 
PHATE. 

318.  IF  THE  CRYSTALS  ARE   LOZENGE-SHAPED,  OR  POS- 
SESS ANY  OF  THE  FORMS  SHOWN  IN  FIGURE  43,  being  in- 

soluble  in  dilute  acids,  but  tolerably  soluble  in  a  solution 
of  potash,  they  are  probably  uric  acid.  (Confirm  288.) 

319.  If  the  crystals  are  OCTOHEDRA  (Fig.  44),  or  some 
modification  of  the  DUMB-BELL  form  (Fig.  45),  insoluble 
in  acetic  acid,  but  really  soluble  in  dilute  hydrochloric 
acid,  they  are  probably  OXALATE  OF  LIME.    (Confirm  287.) 

320.  If  the  crystals  are  MULTANGULAR  PLATES,  having 
the  rosette-like  form  shown  in  Fig.  46,  insoluble,  or  nearly 
so,  in  water  and  dilute  acids,  but  readily  soluble  in  am- 
monia, the  ammoniacal  solution  leaving,  on  evaporation, 
HEXAGONAL   CRYSTALLINE   PLATES  (Fig.   47),  they  are 
probably  CYSTINE  (172). 

321.  IF  THE   DEPOSIT  IS  AMORPHOUS,   OR    IN  MINUTE, 

ROUNDED  PARTICLES,  it  probably  consists  of  PHOSPHATE 

OF   LIME   Or   URATE   OF  AMMONIA  ;    Or   possibly  URATE  OF 

SODA,  FAT,  or  CHYLOUS  MATTER.    See  also  327,  &c. 

322.  If  it  is  INSOLUBLE  WHEN  WARMED,  BUT  DISSOLVES 

IMMEDIATELY  on  the  addition  of  ACETIC  OR  DILUTE  HY- 
DROCHLORIC ACID,  it  is  probably  PHOSPHATE  OF  LIME. 

*  Except  for  high  powers,  the  thin  glass  may  generally  be  dispensed 
with. 


OF    MORBID    URINE. 


133 


Fig.  41. 


Fig.  42. 


Fig.  44. 


Fig.  45. 


134  MICROSCOPIC    EXAMINATION 

Fig.  46.  Fig.  47. 

iT£T>  SZ\          ~. 

O 


O 

323.  If  it  DISSOLVES  READILY  when  the  urine  contain- 
ing it  is  WARMED,  and  is  again  DEPOSITED  ON  COOLING,  it 
is  probably  URATE  OF  SODA  OR  AMMONIA. 

324.  If  the  deposit  is  in  the  form  of  PALE  YELLOWISH 
GRAINS,  with  or  without  small  irregular  protuberances 
(Fig.  48),  DISSOLVING  more  or  less  readily  WHEN  WARMED, 
it  is  probably  URATE  OF  SODA. 

325.  If  the  substance  is  in  the  form  of  MINUTE  ROUND 

GLOBULES,    WITH    DARK    AND    WELL-DEFINED     OUTLINES 

(Fig.  49),  and  DISSOLVES  WHEN  AGITATED  with  ether,  it 
probably  consists  of  FATTY  MATTER.  (Confirm  295.) 

326.  If  the  urine  is  OPAQUE  AND  MILKY  in  appearance, 
yielding  fatty  matter  when  agitated  with  ether,  and  con- 
taining  minute   amorphous,  albuminous   particles,  and 
perhaps   also    colorless   globules,  it   probably    contains 
CHYLOUS  MATTER.     (Confirm  296.) 

327.  IF    THE    DEPOSIT    CONSISTS    OF   ORGANIZED  PAR- 
TICLES, it  probably  consists  either  of  MUCUS  (which  is 
usually  mixed  with  more  or  less  EPITHELIUM),  PUS,  BLOOD, 
or  SEMEN.     See  also  paragraph  132. 

328.  If  the  PARTICLES  ARE  ROUND,  OR  NEARLY  so, 

AND  GRANULATED  on  the  Surface,  ENTANGLED  in  TENA- 
CIOUS, STRINGY  MASSES,  which  do  not  break  up  and  mix 
uniformly  with  the  liquid  on  agitation,  it  is  probably 
MUCUS  (Fig.  50,  a).  EPITHELIAL  DEBRIS  may  be  recog- 
nized by  the  peculiar  forms  of  its  particles  (Fig.  50,  b). 
(156.)  Mucous  urine  very  generally  contains  also  a  con- 
siderable amount  of  earthy  phosphates  and  other  matters. 

329.  If  the  particles  are  ROUND  AND  GRANULAR  (Fig. 
51),  not  being  held  together  by  any  tenacious  matter,  but 
FLOATING  FREELY  IN  THE  LIQUID,  the  deposit  probably 
consists  of  PUS.     (Confirm  290,  156.) 


OF    MORBID    URINE. 


135 


330.  If  the  particles  appear  as  CIRCULAR  AND  SLIGHTLY 
CONCAVE  DISKS,  the  outlines  being  occasionally  irregular 
(Fig.  52),  and  of  a  more  or  less  decided  yellowish  color, 
it  is  probable  that  BLOOD  is  present.     (Confirm  292.) 

331.  If  the  particles,  or  any  among  them,  have  the 
form  of  seminal  animalcules,  or  SPERMATOZOA,  shown  in 
Fig.  53,  SEMEN  is  probably  present. 

332.  The  table  on  page  104  may  be  useful  to  the  stu- 
dent for  reference,  in  the  microscopical  examination  of 
urinary  deposits. 


Fig.  48. 


Fig.  49. 


\ 
-9 


9 

5 

o 


o     © 


Fig.  50. 


136  MICKOSCOPIC    EXAMINATION",  ETC. 

* 

TABLE 

For  facilitating  the  Microscopical  Examination  of  Urinary  Deposits. 

1.  IF  THE   DEPOSIT  IS   CRYSTALLINE,  see  4  to  7. 

2.  IF  AMORPHOUS,  OR  ROUNDED  PARTICLES,  See  8  to  11. 

3.  IF  ORGANIZED  PARTICLES,  see  12  to  16. 

Crystalline. 

4.  LOZENGE-SHAPED  CRYSTALS,  AND  OTHER  FORMS 

SHOWN  in  Figure  43  ;   Uric  acid  (318). 

5.  STELLA  OR  THREE-SIDED  PRISMS  (Figs.  41  and 

42);  Triple  phosphate  (317). 

6.  OCTOHEDRA,  OR  DUMB-BELLS  (Figs.  44  and  45); 

Oxalate  of  lime. 

7.  ROSETTE-LIKE  TABLES  (Fig.  46) ;  Cystine  (320.) 

Amorphous  or  Rounded  Particles. 

8.  SOLUBLE  WHEN  WARMED;    Urate  of  soda  or  am- 

monia  (91,  92,  96). 

9.  SOLUBLE  IN  ACETIC  ACID  ;  Phosphate  of  lime. 

10.  ROUND    GLOBULES    WITH    DARK    EDGES    (Fig.  49); 

Fatty  matter  (325). 

11.  WHITE  AND  MILKY  ;   Chylous  matter?  (326). 

Organized  Particles. 

12.  GRANULATED  CORPUSCLES,  IN  STRINGY  AGGREGA- 

TIONS (Fig.  50) ;  Mucus  (328). 

13.  IRREGULARLY-SHAPED  SCALES  (Fig.  50,  £);  Epithe- 

lium. 

14.  DETACHED    GRANULATED  CORPUSCLES  (Fig.  51); 

Pus  (329). 

15.  BLOOD-CORPUSCLES  (Fig.  52) ;  Blood 

16.  SPERMATOZOA  (Fig.  53) ;  Semen. 


QUANTITATIVE    ANALYSIS,  ETC.  137 


CHAPTER  VII. 

QUANTITATIVE   ANALYSIS  OF   DIABETIC   URINE. 

333.  IN  the  quantitative  examination  of  diabetic  urine, 
it  is  generally  sufficient  to  estimate  merely  the  quantity 
of  sugar,  since  the  determination  of  the  other  consti- 
tuents is  of  comparatively  small  practical  importance  in 
diagnosis.     When  this  is  the  case,  all  that  is  necessary 
is,  to  ferment  250  grs.  of  the  urine  in  the  manner  de- 
scribed below  (336);  and  from  the  amount  of  carbonic 
acid  evolved,  to  estimate  the  quantity  of  sugar  which 
yielded  it. 

334.  It  is,  however,  frequently  of  importance  to  be 
able  to  determine  the  proportion  of  some  of  the  other 
matters  coexisting  in  the  urine,  especially  the  urea  (119), 
which  has  been  supposed  by  some  to  diminish,  and  by 
others  to  increase,  materially  in  quantity,  simultaneously 
with  the  appearance  of  sugar.     The  exact  estimation  of 
small  quantities  of  urea,  when    mixed,   as   in   diabetic 
urine,  with  a  large  amount  of  sugar,  is  attended  with 
considerable  practical  difficulty ;  and,  indeed,  the  results 
hitherto  obtained  must  be  regarded  merely  as  approxi- 
mations to  the  truth.     By  the  method  of  analysis  which 
I  am  about  to  describe,  the  proportions  of  the  following 
substances  may,  without  much  difficulty,  be  determined ; 
or  the  inquiry  may  be  limited  to  the  estimation  of  the 
sugar  and   the   urea   (335,  341):     1,   water;    2,   sugar; 
3,  urea;  4,  uric  acid  and  vesical  mucus;  5,  animal  ex- 
tractive and  ammoniacal  salts;  6,  fixed  alkaline  salts; 
and  7,  earthy  salts. 

335.  Two  portions  of  the  urine,  A  weighing  1000  grs., 
and  B  weighing  500  grs.,  are  to  be  evaporated  to  dry- 
ness  (50),  in  weighed  or  counterpoised  dishes,  on  a  water 
or  chloride  of  calcium  bath;  or,  still   better,  in  vacuo, 
over  sulphuric  acid.     While  the  evaporation  of  A  and  B 

12* 


138  QUANTITATIVE    ANALYSIS    OF 

is  going  on,  a  third  portion,  C,  consisting  of  250  grs.  of 
the  urine,  may  be  weighed  out,  for  the  purpose  of  esti- 
mating the  sugar,  which  is  done  in  the  following  manner 
(336). 

336.  Treatment  of  the  portion  C*— Put  250  grs.  of  the 

urine    into    a    small   wide-mouthed 
Fig.  54.  bottle,  capable  of  holding  an  ounce 

____«_,, and  a  half  or  two  ounces  of  water ; 

to  the  mouth  of  which  is  adapted  a 
cork,  fitted  with  tubes  of  the  form 
shown  in  the  figure  (Fig.  54).  The 
bottle  should  be  graduated  in  cubic 
inches  and  tenths,  in  order  to  enable 
the  experimenter  to  estimate  the 
amount  of  carbonic  acid  which  is 
retained  in  solution  by  the  liquid  at 
the  close  of  the  operation  (338).  The 
tube  a  is  nearly  filled  with  small  fragments  of  dry  chloride 
of  calcium,  which  are  prevented  from  falling  out  by  a 
loose  plug  of  cotton  wool  placed  at  each  end.  The  tube, 
b,  which  reaches  nearly  to  the  bottom,  is  made  open  at 
both  ends ;  the  top,  however,  being  accurately  closed  by 
means  of  a  small  bit  of  cork  or  wax,  c,  during  the  pro- 
cess of  fermentation. 

337.  Mix  a  few  drops  of  fresh  yeast,  or,  still  better, 
about  fifty  grains  of  dry  German  yeast  (128),  with  the 
urine  in  the  bottle;  and  having  placed  the  cork,  with  its 
tubes,  firmly  in  the  neck,  weigh  the  whole  apparatus, 
with  its  contents,  as  accurately  as  possible.     Allow  the 
apparatus  to  stand  a  day  or  two  in  a  warm  place,  having 
a  temperature  of  about  70°  or  80° ;  and  when  the  fer- 
mentation appears  to  have  entirely  ceased,  remove  the 
small  plug  of  cork  or  wax  from  the  tube  &,  and  suck  air 
gently  from  a,  for  the  purpose  of  expelling  the  carbonic 
acid  contained  in  the  bottle,  and  replacing  it  with  com- 
mon air.     The  small  plug  is  then  attached  to  the  tube  &, 
as  before,  and  the  whole  apparatus  is  again  weighed. 

338.  The  amount  of  loss  will  indicate  the  quantity  of 

*  Although  this  method  will  furnish  only  a  rough  estimate  of  the 
sugar  present,  the  experiment  is  an  instructive  one  for  the  student. 


DIABETIC    URINE.  139 

carbonic  acid  which  has  escaped  through  the  tube  a;  but 
as  carbonic  acid  is  soluble,  at  ordinary  temperatures,  in 
about  its  own  bulk  of  water,  the  portion  of  acid  held  in 
solution  by  the  liquid  must  be  added  to  that  which  has 
escaped.  This  amount  is  readily  known,  since  each 
cubic  inch  of  liquid,  which  may  be  supposed  to  be  satu- 
rated with  the  acid,  must  contain  about  a  cubic  inch  of 
the  gas,  weighing  rather  less  than  half  a  grain.* 

339.  The  whole  amount  of  carbonic  acid  formed  during 
fermentation,  therefore,  is  determined  by  adding  to   the 
loss  of  weight  half  a  grain  for  every  cubic  inch  of  liquid 
contained  in  the  bottle,  the  quantity  of  which  is  known 
by  the  graduations  on  the  surface  (336)..    Thus,  suppos- 
ing the  loss  of  weight  during  fermentation  to  have  been 
4'1  grs.,  and  the  volume  of  liquid  in  the  bottle  1'2  cubic 
inch,  the  weight  of  the  carbonic  acid  formed  must  be  4*1 
4-  l;^,  or  4*7  grains. 

340.  Now,  since  every  equivalent  of  diabetic  sugar 
(C12H14O14)  is  converted,  during  fermentation,  into   two 
equivalents   of   alcohol    (C4HS0,HO),   four   equivalents 
of  carbonic  acid  (C02),  and  two  equivalents  of  water 


c«Hu°i4  =  2(0^,0,170)  -f  4G02  4.  4HO  ; 
it  follows  that  every  198  parts  by  weight  of  sugar  (one 
equivalent)  give  rise  to  the  formation  of  88  parts  of  car- 
bonic acid  (four  equivalents);  so  that  every  88  grs.  of 
carbonic  acid  would  indicate  198  grs.  of  sugar,  or,  in  other 
words,  one  gr.  of  carbonic  acid  will  represent  2*25  grs. 
of  sugar.  Therefore,  by  multiplying  the  weight  of  car- 
bonic acid  by  2*25,  we  obtain  the  weight  of  SUGAR  present 
in  the  quantity  of  urine  operated  on.  Thus,  in  the  above 
example,  4*7  grs.  multiplied  by  2*25  (  =  10*57)  gives  the 
weight  of  sugar  in  250  grs.  of  urine;  which,  when  multi- 
plied by  four  (250x4=1000),  represents  the  proportion 
in  1000  grs.  of  the  secretion. 

341.  Treatment  of  the  portion  A.  —  The  dry  residue  left 
after  the  evaporation  of  the  1000  grs.  marked  A  (335),  is 

*  One  hundred  cubic  inches  of  carbonic  acid  weigh  47*30  grains  ; 
one  cubic  inch,  consequently,  weighs  0-47  of  a  grain. 
f   See  not.-  to  129. 


140  QUANTITATIVE    ANALYSIS    OF 

to  be  used  for  estimating  the  urea,  which  is  usually  pre- 
sent only  in  minute  proportion  in  diabetic  urine.  For 
this  purpose,  the  residue  is  treated  with  successive  small 
quantities  of  alcohol,  stirring  the  mixture  with  a  glass 
rod,  until  it  ceases  to  dissolve  anything  more.  The 
alcoholic  solution  is  now  to  be  evaporated  to  dryness  on 
a  water-bath,  and  the  residue  treated  with  strong  alcohol 
(absolute  alcohol,  if  possible,  114),  which  will  dissolve 
out  the  urea,  leaving  undissolved  most  of  the  sugar  and 
other  matters.  The  alcoholic  solution  thus  obtained  is 
to  be  again  evaporated  to  dryness  on  a  water  bath,  and 
the  residue  treated,  as  long  as  anything  dissolves,  with 
warm  distilled  water,  which  will  separate  the  urea  from 
most  of  the  other  matters  which  are  less  soluble  in  water. 

842.  The  impure  aqueous  solution  of  urea  thus  obtained 
is  evaporated  to  a  small  bulk,  and  while  at  a  temperature 
of  about  190°  or  200°,  mixeo^  with  as  much  pounded 
oxalic  acid  (HO,C2O3+'2Aq)  as  will  dissolve  in  the  liquid 
(14).  The  mixture,  after  cooling,  is  immersed  in  a 
freezing  mixture,*  when  the  whole  of  the  oxalate  of  urea, 
together  with  the  excess  of  oxalic  acid,  will  crystallize 
out.  The  liquid  is  now  to  be  poured  off,  and  the  crystals 
further  treated  as  in  55. 

343.  Treatment  of  the  portion  B. — The  residue  left  after 
the  evaporation  of  the  500  grs.  of  urine  marked  B,  may 
now  be  examined,  for  the  purpose  of  estimating,  1,  the 
water;  2,  uric  acid  and  vesical  mucus;  3,  animal  extrac- 
tive and  ammoniacal  salts;  4,  fixed  alkaline  salts;  and  5, 
earthy  salts.  For  this  purpose  it  is  be  carefully  evapo- 
rated until  it  ceases  to  lose  weight,  either  on  a  water  or 
chloride  of  calcium  bath,  or,  still  better,  in  vacuo  over 
sulphuric  acid ;  since  by  long  exposure  to  a  high  tem- 
perature a  portion  of  the  sugar  loses  five  equivalents  of 
water,  and  becomes  converted  into  a  kind  of  uncrystal- 
lizable  caramel,  thus  causing  the  residue  to  weigh  less 
than  it  ought  to  do.  It  is-  generally  a  matter  of  con- 
siderable difficulty  to  expel  the  last  traces  of  water  from 

*  A  little  pounded  ice  or  snow,  mixed  with  about  half  its  weight 
of  common  salt ;  or,  in  the  absence  of  ice,  a  mixture  of  equal  weights 
of  nitrate  of  ammonia  and  water,  will  be  found  the  most  convenient 
freezing  mixture. 


DIABETIC   URINE.  141 

the  residue  of  diabetic  urine:  for  the  ordinary  purposes, 
however,  this  is  not  of  much  importance,  since  the  small 
error  which  it  here  occasions  affects  only  the  proportion 
of  the  water  and  animal  extractive,  and  not  that  of  the 
two  substances  of  most  importance — viz.,  the  sugar  arid 
the  urea. 

344.  The  dry  residue  B  is  to  be  weighed;  and  by 
deducting  its  weight  from  that  of  the  urine  before  evapo- 
ration (500  grs.),  the  proportion  of  water  is  determined ; 
which,  when  multiplied  by  two  (500x2  =  1000),  gives 
the  proportion  of  WATER  in  1000  grs.  of  the  secretion. 

345.  The  weight  of  the  dry  residue  having  been  care- 
fully noted,  it  is  to  be  treated  with  water  as  long  as  any- 
thing appears  to  dissolve.     In  this  way  the  sugar,  urea, 
animal  extractive,  and  alkaline  salts  are  dissolved  out, 
leaving  a  small  insoluble  residue,  consisting  of  vesical 
mucus,  uric  acid,  earthy  phosphates,  and  traces  of  silica. 

346.  The  aqueous  solution  thus  formed  is  to  be  evapo- 
rated to  dryness  on  a  water-bath,  and  retained  for  subse- 
quent experiments  (349). 

347.  The  weight  of  the  matter  insoluble  in  water  (345), 
having  been  noted  after  careful  drying,  it  is  to  be  incine- 
rated until  the  residue  becomes  white  or  pale  gray.    The 
ash    thus   obtained  is  to  be  weighed;    and  its  weight, 
multiplied  by  two,  furnishes  the  proportion  of  EARTHY 
SALTS  in  1000  grains  of  the  urine. 

348.  The  difference  between  the  weight  of  the  ash  and 
that  of  the  dry  insoluble  residue  previous  to  ignition 
(347),  represents  the  quantity  of  insoluble  organic  matter, 
consisting  of  URIC  ACID  and  MUCUS,  in  500  grains  of  the 
urine ;  which  must  be  multiplied  by  two,  as  in  the  former 
cases,  in  order  to  give  the  proportion  in  1000  grains  of 
the  secretion. 

349.  The   dry  residue   obtained   by   evaporating  the 
aqueous  solution  (346),  consisting  of  the  soluble  matters 
of  the  urine,  is  now  to  be  weighed.     It  consists  of  two 
portions,  the  organic  or  combustible,  and  the  inorganic 
or  incombustible.     The  relative  amounts  of  these  two 
portions  are  determined  by  incineration ;  the  weight  of 
the  ash  representing  the  FIXED  ALKALINE  SALTS  in  500 
grains ;  which,  as  before,  is  to  be  multiplied  by  two. 


142  QUANTITATIVE    ANALYSIS    OF 

350.  The  loss  of  weight  experienced  during  incinera- 
tion (349),  which  is  that  of  the  soluble  combustible  mat- 
ters, viz.,  sugar,  urea,  animal  extractive,  and  ammoniacal 
salts,  is  also  to  be  multiplied  by  two.     Now,  since  we 
know  from  our  experiments  with  the  other  portions  of 
urine  A  and  C,  the  weight  of  the  sugar  and  urea  (340, 
342),  we  can,  by  deducting  their  combined  weights  from 
the  amount  of  loss  during  ignition,  obtain  the  proportion 
of  ANIMAL  EXTRACTIVE  and  AMMONIACAL  SALTS  contained 
in  1000  grains  of  the  urine. 

351.  Thus  we  shall  have  determined  the  proportions 
of  the  several  ingredients  of  the  urine,  which  together 
should  amount  to  a  fraction  less  than  1000,  viz : — 

Water 

Sugar          

Urea 

Uric  acid  and  mucus 

Animal  extract  and  ammoniacal  salt  . 

Fixed  alkaline  salts    ...... 

Earthy  salts        ....... 

Loss 

1000-00 

352.  One  of  the  best  methods  of  estimating  the  sugar 
is  founded  upon  its  property  of  reducing  the  oxide  of 
copper  (CuO),  in  an  alkaline  solution,  to  the  state  of  sub- 
oxide  (Cu2O),  one  equivalent  of  grape-sugar  (C]2H14014) 
effecting  the  reduction  of  ten  equivalents  of  the  oxide. 

To  prepare  the  alkaline  solution  of  oxide  of  copper, 
advantage  is  taken  of  the  circumstances  that  the  presence 
of  tartaric  acid  or  a  tartrate,  enables  the  fixed  alkalies 
to  retain  the  oxide  in  solution ;  and  if  there  be  a  suffi- 
ciently large  excess  of  caustic  alkali  present,  the  solution 
may  be  boiled  without  alteration. 

315*16  grs.  of  crystallized  sulphate  of  copper  are  dis- 
solved in  about  four  ounces  of  water,  and  1420  grs.  of 
the  tartrate  of  potash  and  soda*  (Rochelle  salt,  KO,NaO, 
C8H4010+8Aq)  are  powdered,  and  added  gradually  to 

*  950  grs.  of  pure  cream  of  tartar  (bitartrate  of  potash,  KO,HO, 
C8H4010)  might  be  substituted  for  the  Rochelle  salt,  but  the  latter  is 
preferable,  as  being  more  easily  obtained  in  a  pure  state. 


DIABETIC    URINE.  143 

the  solution.  480  grs.  of  carbonate  of  potash  are  then 
added,  and  8J  fluidounces  of  a  solution  of  hydrate  of 
soda  (caustic  soda)  of  sp.  gr.  T12.  The  volume  of  the 
mixture  is  made  up  to  10,000  grs.  by  adding  water,  the 
whole  boiled  for  a  few  minutes,  and,  if  necessary,  filtered. 
1000  grain-measures  of  this  solution  should  correspond 
to  5  grs.  of  grape-sugar  (C12II14O14). 

In  order  to  ascertain  its  exact  strength,  4'32  grs.  of 
pure  cane-sugar*  (white  sugar-candy,  C^H^On)  are  dis- 
solved in  a  little  water,  in  a  flask,  a  few  drops  of  dilute 
sulphuric  acid  added,  and  the  mixture  boiled  for  an  hour 
(replacing  the  water  as  it  evaporates),  in  order  to  convert 
the  cane-sugar  into  grape-sugar.  The  solution  is  then 
rendered  slightly  alkaline  with  carbonate  of  soda,  and 
its  volume  is  made  up  to  1000  grs.  with  water.  500 
grain-measures  of  the  alkaline  copper  solution  are  heated 
to  boiling  in  a  beaker  or  dish,  and  the  solution  of  sugar 
gradually  added  from  a  burette  or  graduated  glass  (Fig. 
32),  until  the  disappearance  of  the  blue  color,  and  the 
non-occurrence  of  any  fresh  precipitate  prove  that  the 
whole  of  the  oxide  of  copper  has  been  reduced.  If  the 
copper  solution  was  correctly  prepared,  500  grs.  of  the 
sugar  solution  should  have  been  required ;  but  if  more 
or  less  than  this  have  been  found  necessary,  it  is  easy  to 
calculate  the  exact  strength  of  the  copper  solution,  which 
should  then  be  recorded  upon  the  label  of  the  bottle, 
together  with  the  date  of  the  experiment.  For  example, 
suppose  455  grs.  of  the  sugar  solution  to  have  completed 
the  reduction,  then 

Grs.  of  sugar-solution.        Grape-sugar.        Sugar-solution  used. 


1000  :  5          :  :  455  :         x 

The  value  of  x  will  represent  the  weight  of  grape-sugar 
to  which  500  grain-measures  of  the  copper  solution  cor- 
respond. The  solution  must  be  kept  in  a  well-stopped 
bottle,  which  should  be  nearly  filled  by  it,  and  set  aside 
in  a  dark  place. 

To  determine  the  amount  of  sugar  in  diabetic  urine, 

*  Which  will  yield  5  grs.  of  grape-sugar.     It  would  be  better  to 
employ  5  grains  of  pure  grape-sugar,  but  this  is  not  so  easily  obtained. 


144  QUANTITATIVE    ANALYSIS    OF 

750  grain-measures  of  the  urine  are  precipitated  by  a 
solution  of  tribasic  acetate  of  lead,  added  in  very  small 
portions,  with  occasional  stirring,  as  long  as  any  fresh 
precipitate  is  observed.  The  precipitate  (phosphate,  sul 
phate,  and  urate  of  lead,  with  extractive  matters)  is  filtered 
off,  and  washed  with  a  little  water,  so  as  to  make  the  total 
volume  of  the  filtrate  and  washings  up  to  1000  grs.  500 
grain-measures  of  the  alkaline  copper  solution  are  then 
heated  to  boiling,  and  the  purified  urine  added  from  a 
burette,  until  the  blue  color  of  the  solution  has  disap- 
peared. A  simple  calculation  will  then  give  the  amount 
of  sugar  contained  in  the  750  grs.  of  urine  originally 
employed. 

A  very  excellent  method  of  controlling  the  result  of 
this  experiment  consists  in  adding  to  the  solution  from 
which  the  blue  color  has  disappeared  enough  of  the  alka- 
line copper  solution  to  restore  the  blue  color,  boiling  for 
a  few  seconds,  and  collecting  the  precipitated  suboxide 
of  copper  upon  a  filter.  It  is  then  rapidly  washed,  as 
long  as  the  washings  are  alkaline,  and  dissolved  by  pour- 
ing over  the  filter  a  hot  solution  of  perchloride  of  iron, 
acidulated  with  hydrochloric  acid,  when  the  suboxide  of 
copper  (Cu20)  is  converted  into  the  chloride  (CuCl): 
Cu20  -f  Fe2Cl3  -f  HC1  ==  2CuCl  +  2FeCl  -f  HO. 

The  filter  is  washed  with  much  water,  and  the  amount  of 
iron  in  the  state  of  protochloride  (FeCl)  is  determined  by 
adding  a  solution  of  permanganate  of  potash  of  known 
strength*  from  a  burette,  until  a  permanent  faint  rose 
color  is  produced. 

Now,  each  atom  (198  parts)  of  grape  sugar  (C12H14014) 
precipitates  five  atoms  (357  parts)  of  suboxide  of  copper 
(Cu20),  and  these,  when  dissolved  in  perchloride  of  iron, 
produce  ten  atoms  of  protochloride  of  iron  (Fed),  con- 
taining 280  parts  of  iron.  Hence  every  grain  of  iron 
indicated  by  the  permanganate  of  potash  represents  0'707 
gr.  of  grape-sugar. 

*  The  strength  of  this  solution  is  readily  determined  by  dissolving 
5  grs.  of  pure  iron  wire  in  hydrochloric  acid,  diluting  largely  with 
water,  and  adding  the  permanganate  solution,  from  a  burette,  till  the 
permanent  rose  color  is  seen.  About  1000  grs.  of  the  solution  should 
be  required  for  5  grs.  of  iron. 


DIABETIC    URINE. 


145 


A  slight  error  occurs  in  the  determination  of  sugar  in 
urine  according  to  this  process,  from  the  precipitation  of 
a  little  sugar  by  the  tribasic  acetate  of  lead ;  for  although 
a  pure  solution  of  sugar  is  not  precipitated  by  that  re- 
agent, the  precipitate  which  it  causes  in  saccharine  urine 
is  always  accompanied  by  a  little  sugar.  In  most  cases 
this  error  is  too  slight  to  be  of  any  consequence,  but  its 
extent  may  be  easily  ascertained  by  boiling  the  lead  pre- 
cipitate with  oxalic  acid,  filtering,  mixing  the  solution 
with  an  excess  of  potash,  and  determining  the  sugar  by 
the  alkaline  copper  solution.  This  will  give  a  slight 
error  in  the  opposite  direction,  on  account  of  the  reduc- 
tion of  the  oxide  of  copper  by  the  uric  acid. 

The  following  analyses  of  diabetic  urine  will  serve  to 
illustrate  its  usual  composition  in  1000  parts: — 

Analyses  I  and  II, 


Water 

Solid  constituents 

Urea. 

Uric  acid 

Sugar 

Extractive  matter  and 

Earthy  phosphates 

Albumen    . 


1018 

1016 

957-00 

960-00 

43-00 

40-00 

traces 

7-99 

traces 

traces 

39-80 

25-00 

I  soli 

ble  s 

alts 

2-10 

6-50 

0-52 

0-80 

traces 

traces 

Analyses  III,  IV,  and  V.    {Dr.  Percy.) 


III. 

IV. 

V. 

Specific  gravity                             1042 

1035 

1039 

Water  . 

894-50 

918-30 

898-90 

Solid  constituents 

105-50 

81-70 

101-10 

Urea 

12-16 

30-32 

2-39 

Uric  acid  . 

0-16 

0-26 

not  isolated 

Sugar 

40-12 

17-15 

79-10 

Extractive  matters 
soluble  salts  . 

lud  }        53-06 

32-59 

19-52 

Earthy  phosphates 

. 

1-30 

0-09 

Analysis  VI.    (BoucharJat.) 
Water 
Solid  constituents 

Urea 

Uric  acid 

Sugar 

Extractive  matters  and  soluble  salts 

Earthy  phosphates  .... 

13 


837-58 

162-42 

8-27 

not  isolated 
134.42 
20-34 
0-38 


146  QUANTITATIVE    ANALYSIS    OF 


CHAPTER  VIII. 

QUANTITATIVE   ANALYSIS  OF  ALBUMINOUS   URINE. 

353.  IN  the  quantitative  analysis  of  albuminous  urine, 
it  is  usual  to  estimate  the  following  ingredients;  though 
for  many  purposes  it  is  sufficient  merely  to  determine*  the 
proportion  of  albumen,  either  with  or  without  that  of  the 
urea:     1,  water;  2,  urea;  3,  albumen,  with  traces  of  uric 
acid;*  4,  vesical  mucus;    5,  animal  extractive  and  am- 
moniacal  salts;    6,  fixed  alkaline   salts;    and  7,  earthy 
salts. 

354.  Treatment  of  the  portion  A. — Two  portions  of  the 
urine,  marked  respectively  A  and  B,  each  weighing  500 
grains,  are  to  be  evaporated  to  dryness  on  a  water-bath.f 
The  portion  A  will  serve  for  the  estimation  of  the  urea  ; 
and  the  portion  B  for  that  of  the  other  substances  above 
enumerated. 

355.  The  residue  left  after  the  evaporation  of  A  is 
treated  with  hot  alcohol,  to  dissolve  out  the  urea.     The 
alcoholic  solution  is  evaporated  to  dryness  on  a  water- 
bath,  and  redissolved,  as  far  as  it  is  capable,  in  hot  dis- 
tilled water ;  the  aqueous  solution  thus  obtained  is  eva- 
porated to  a  small  bulk,  and  mixed  with  pounded  oxalic 
acid  in  the  manner  described  in  the  analysis  of  diabetic 
urine  (342).     The  oxalate  of  urea  is  afterwards  decom- 
posed  by  means  of  carbonate  of  lime  in   the  manner 
already  detailed ;  the  weight  of  the  urea  obtained  being 
multiplied  by  two,  in  order  to  represent  the  proportion 
of  UREA  in  1000  grains  of  the  urine. J 

*  Or  the  uric  acid  may  be  estimated  separately.    See  paragraph  363. 

f  If  it  is  intended  to  estimate  the  uric  acid  separately,  a  third  portion 
of  urine,  weighing  1000  grs.,  will  also  be  required  (363). 

J  A  far  more  accurate  result  would,  of  course,  be  obtained  by  heat- 
ing the  urine  (acidified,  if  necessary,  with  acetic  acid)  to  coagulate 
the  albumen,  and  determining  the  urea  in  the  filtered  liquid  according 
to  (182). 


ALBUMINOUS    URINE.  147 

356.  Treatment  of  the  portion  B. — The  residue  left  after 
the  evaporation  of  B  is  now  to  be  examined.     When  it 
has  ceased  to  lose  weight  by  exposure  on  the  water-bath, 
the  weight  of  the  residue  is  to  be  noted;  and  the  loss 
which  it  has  sustained  during  evaporation,  multiplied  by 
two,  will  represent  the  amount  of  WATER  in  1000  grains 
of  urine. 

357.  The  dry  residue,  when  cold,  is  to  be  carefully 
reduced  to  powder  in  a  clean  dry  mortar,  which  should 
be  placed  on  a  large  sheet  of  white  paper,  in  order  to 
catch  any  particles  that  may  be  projected  out  of  the  mortar 
during  the  pounding.     The  powder  is  to  be  warmed  with 
distilled  water,  which  will  dissolve  out  the  urea,  animal 
extractive,  and  soluble  salts;  leaving  an  insoluble  residue 
of  coagulated   albumen,  uric   acid,   mucus,  and   earthy 
salts.     The  mixture  is  then  filtered.     The  solution  thus 
obtained  we  call  M,  and  the  insoluble  matter  N. 

358.  The  solution  M  is  to  be  evaporated  to  dryness  on 
a  water-bath,  and  subsequently  examined  in  the  manner 
described  below  (361).     While  the  evaporation  is  going 
on,  the  insoluble  matter  N  may  be  operated  on  (359). 

359.  The  insoluble  matter  N,  consisting  of  albumen, 
uric  acid,  mucus,  and  earthy  salts,  is  to  be  carefully  de- 
tached from  the  filter  whilst  still  moist.   It  is  then  warmed 
for  a  few  seconds  with  a  little  dilute  nitric  acid  (consist- 
ing of  one  part  of  strong  acid,  and  about  ten  parts  of 
water),  and  well  stirred  with  a  glass  rod,  in  order  to 
dissolve  out  the  earthy  phosphates.     The  insoluble  por- 
tion is  to  be  washed  with  a  little  warm  water  (360),  and 
the   acid    solution,    together   with    the    washings,    then 
evaporated  to  dryness  on  a  water-bath.     The  dry  residue 
is  weighed,  incinerated,  and  weighed   again ;  when  the 
weight  of  the  incombustible  matter,  multiplied  by  two, 
will  represent  the  proportion  of  EARTHY  PHOSPHATES  in 
1000  parts  of  the  urine;  while  the  loss  which  the  mixture 
sustained  during  the  incineration,  also  multiplied  by  two, 
will  represent  the  amount  of  VESICAL  MUCUS. 

360.  The  portion  of  N  which  proved  insoluble  in  the 
dilute   nitric   acid   (359),    consisting   of  albumen,   with 
probably  a  little  uric  acid,  is  to  be  dried  on  a  water-bath, 
and  weighed.     The  weight  multiplied  by  two,  will  repre- 


148  QUANTITATIVE    ANALYSIS    OF 

sent  the  proportion  of  ALBUMEN  and  UKIC  ACID  in  1000 
grains  of  the  urine. 

361.  The  evaporated  residue  left  by  the  solution  M 
(358),  containing  the  urea,  animal  extractive,  and  soluble 
salts,  must  now  be  examined.     After  its  weight  has  been 
ascertained,  the  dry  residue  is  to  be  gently  ignited  until 
the  incombustible  matter  becomes  white  or  pale  gray. 
The  ash  thus  obtained  is  then  weighed ;  and  its  weight, 
multiplied  by  two,  will  represent  the  proportion  of  FIXED 
ALKALINE  SALTS  in  1000  grains  of  the  urine.* 

362.  The  loss  of  weight  which  the  residue  sustained 
during  incineration  (361)  being  due  to  the  combustion 
of  the  urea  and  animal  extractive,  and  the  volatilization 
of  the  ammoniacal  salts,  derived  from   500  grains  of 
urine;  we  obtain,  by  doubling  it,  the  amount  of  those 
substances  contained  in  100  grains.     From  this  we  deduct 
the  proportion  of  urea,  which  we  have  already  ascer- 
tained (355),  and  the  difference  will  represent  the  amount 
of  ANIMAL  EXTRACTIVE  and  AMMONIACAL  SALTS  contained 
in  1000  grains  of  the  secretion. 

363.  If  it  is  required  to  estimate  the  proportion  of  uric 
acid    in    albuminous    urine,  which,  however,  is    seldom 
necessary,  since  there   is  not  often  more  than  a  small 
trace  of  it  present,  a  separate  portion  of  urine  must  be 
used  for  the  experiment.     For  this  purpose,  1000  grains 
are  to  be  boiled  for  about  a  quarter  of  an  hour  and 
filtered  from  the  coagulated  albumen.  The  filtered  liquid 
is  then  concentrated  to  about  one-fourth   its  bulk,  by 
evaporation  on  a  water-bath,  and,  after  the  addition  of 
a  few  drops  of  hydrochloric  acid,  set  aside  in  a  cool  place 
for  forty-eight  hours.     The  UKIC  ACID,  if  present  in  any 
notable  quantity,  will  gradually  crystallize  out,  mixed 
possibly  with  traces  of  hippuric  acid  (25),  which  may  be 
washed  out  with  a  little  alcohol  (28).     The  weight  of  the 
residue  will  then,  after  drying  on  a  water-bath,  represent 
the  proportion  of  the  acid  in  1000  grains  of  urine. 

364.  Thus  we  shall  have  completed  the  analysis,  having 
determined  the  proportion  of  the  several  ingredients  pro- 

*  During  this  ignition,  traces  of  the  alkaline  chlorides  are  always 
volatilized,  causing  a  slight  loss. 


ALBUMINOUS    URINE.  149 

posed ;  which,  when  added  together,  should  amount  to 
a  fraction  less  than  1000  grains,  viz. — 

Water 

Urea 

Albumen         ...... 

Uric  acid          ...... 

Vesical  mucus 

Animal  extractive  and  ainmoniacal  salts 
Fixed  alkaline  salts         .... 

Earthy  salts 

Loss 

1000-00 


365.  The  following  analyses  of  albuminous  urine,  in 
cases  of  Bright's  disease,  will  serve  to  show  its  usual 
composition  in  1000  parts : — 

Analyses  I  and  II.    (Simon.) 

i.  n. 

Specific  gravity        ....  1014  1022 

Water 966-10  933-50 

Solid  constituents  ....       33-90  66-50 

Urea 4-77  10-10 

Uric  acid 0-40  0-60 

Fixed  salts 8-04  10-00 

Extractive  matters       .         .         .         2-40  

Albumen 18-00  33-60 

Analysis  III.    (Dr.  Percy.) 

Specific  gravity 1020 

Water    " 946-82 

Solid  constituents 53-18 

Urea 7-68 

Uric  acid  and  indeterminate  animal  matter  17-52 

Fixed  soluble  salts 5-20 

Earthy  phosphates 0-14 

Albumen      .         .  22-64 


13* 


PART  II. 

CALCULI    AND. CONCRETIONS. 


CHAPTER  I. 

URINARY     CALCULI. 


SECTION  I. 

366.  URINARY  calculi  are  composed,  in  the  great  ma- 
jority of  cases,  of  substances  which  are  contained   in 
healthy  urine,  such  as  uric  acid,  urate  of  ammonia,  and 
the  phosphates  of  lime  and  magnesia ;  they  are,  however, 
occasionally  composed  of  substances  which  are  met  with 
only  in   morbid  urine,  such  as  oxalate  of  lime,  cystine, 
&c.     Other  substances  also,  which  may  strictly  be  called 
accidental,  are  occasionally  contained  in  calculi ;  such  as 
fragments  of  sand,   or  other  hard  bodies,   which    have 
accidentally  found  their  way  into  the  kidneys  or  bladder, 
and  there  formed   nuclei,  round  which  the  earthy  phos- 
phates, or  other  matters,  have  gradually  been  deposited. 
Calculi  always  contain,  in  addition  to  the  ingredients  of 
which  they  mainly  consist,  more  or  less  animal  matter, 
such  as  dried  blood  and  urine,  vesical  mucus,  &c. 

367.  Calculi  are  found  to  consist  occasionally  almost 
entirely  of  one  ingredient  only,  but  more  frequently  of 
two  or  more  different  constituents  arranged  together  in 
irregular  concentric  layers.     On   this  account  it  is  im- 
possible to  determine,  with  any  degree  of  certainty,  the 
nature  of  the  mass  of  a  calculus,  by  merely  examining 
the  external  coating,  since  the  more  central  portion  may 
be  of  a  nature  wholly  different.     The   best   way   is  to 


URINARY    CALCULI. 


L51 


divide  the  calculus  into  two  equal  parts,  which  is  easily 
done  by  carefully  cutting  it  through  the  centre  with  a 
fine  saw.     Kig.  55   represents  a 
mixed  calculus  divided  in  this  Fi8-  55- 

manner ;  the  darker  layers  con- 
sisted, in  the  specimen  from 
which  the  drawing  was  made, 
of  oxalate  of  lime,  and  the 
lighter  rings  of  uric  acid.  When 
a  calculus  is  thus  found  on  ex- 
amination to  consist  apparently 
of  two  or  more  kinds  of  matter, 
fragments  of  each  kind  should  Alternating  calculus, 

be  carefully  detached  and  sepa- 
rately examined  (411  ).* 

SECTION  II. 
Uric  (orLithic)  Acid  (C10H4N406). 

368.  Uric  acid  calculi  are  usually  smooth  or  slightly 
tuberculated  on  the  surface  (Fig.  56),  and  of  colors  vary- 
ing from  pale  yellowish  fawn  to  reddish  brown.     When 
sawn    through,    the    layers    will 

generally  be  found  to  be  tolerably  Fig-  56. 

regular,  though  of  different  thick- 
nesses, and  nearly  parallel  to  the 
outline  of  the  section.  This  is  the 
most  common  of  all  the  urinary 
calculi. 

369.  Heat  a  small  fragment  of 

the  calculus  on  platinum  foil;    it  uric Acia calculus, 

immediately    blackens,    owing   to 

the  charring  of  the  animal  matter,  emitting,  at  the  same 
time,  a  disagreeable  smell,  resembling  that  of  burntfeathers, 
mixed  with  that  of  hydrocyanic  acid  (H,C2N),  which, 
together  with  carbonate  of  ammonia  and  some  other 
compounds,  is  formed  during  the  decomposition.  If  the 
heat  be  continued,  the  charcoal  residue  is  gradually  con- 


*  A  small  fragment  of  the  calculus,  about  the  size  of  a  pin's  head,  is 
£« 'mi rally  sufficient  for  each  experiment,  and  will  be  found  more  con- 
vnient  in  practice  than  a  larger  quantity. 


152  URINARY    CALCULI. 

sumed,  leaving  only  a  slight  trace  of  ash,  which  is  usually 
alkaline  to  test-paper,  consisting  of  phosphate  or  carbon- 
ate of  soda.  Traces  of  the  earthy  phosphates,  also,  are 
almost  always  to  be  found  in  this  and  most  other  varieties 
of  calculi. 

370.  Uric  acid  is  sparingly  soluble  in  water,  and  in 
cold  dilute  acids  (22). 

371.  A  little  of  the  calculus  in  powder  is  placed  in  a 
drop  or  two  of  tolerably  strong  nitric  acid,  in  a  watch- 
glass,  or  on  a  strip  of  glass  or  platinum  ;  it  dissolves  with 
effervescence,  carbonic  acid  and  nitrogen  being  given  off, 
and    a    mixture    of    alloxan    (C8H4N2O10),    alloxantine 
(C8H5N2010),  and  some  other  compounds,  remains.     This 
is  evaporated  to  dryness,  at  a  gentle  heat,  when  a  red 
residue  is  left,  which,  when  cold,  and  treated  with  a  drop 
of  ammonia,  or  exposed  to  ammoniacal  fumes,  becomes 
purple,  owing  to  the  formation  of  murexide  (C12H6N5O8). 

372.  Uric  acid  calculus  dissolves  in  a  dilute  solution 
of  potash,  leaving  only  a  few  shreds  of  animal  matter 
(366) ;  and  when  the  mixture  is  warmed,  no  smell  of  am- 
monia is  perceptible,  thus  differing  from  the  urate  of 
ammonia  (377).     On  neutralizing  the  alkaline  solution 
with  any  acid,  as  hydrochloric,  a  white  precipitate  of  pure 
uric  acid   is  thrown  down,  which,  when   separated  by 
filtration,  may  be  tested  with  nitric  acid  and  ammonia,  as 
described  in  371. 

373.  If  the  precipitated  uric  acid  be  examined  under 
the  microscope,  it  will  be  found  to  consist  of  minute 
crystals,  having  the  form  shown  in  Fig.  3,  page  32.* 

*  Xanthic  or  Uric  Oxide  or  Xanthine  (C]0H4N404),  which  com- 
poses a  very  rare  form  of  calculus,  als6  dissolves  in  potash,  and  is 
reprecipitated  by  hydrochloric  acid.  When  dissolved  in  nitric  acid, 
however,  it  leaves  a  yellow  residue  on  evaporation,  which  is  not 
reddened  by  ammonia.  Xanthic  oxide  has  also  been  found  in  nor- 
mal urine,  and  in  the  spleen,  pancreas,  brain,  and  liver  of  oxen  and 
other  animals.  Hypoxanthine  (CIOH4N402)  is  very  similar  in  its  pro- 
perties, and  has  also  been  found  in  the  spleen.  Dr.  Bence  Jones  has 
observed,  in  one  case  in  the  urine,  a  deposit  which  had  the  chemical 
characters  of  xanthic  oxide,  and  appeared,  under  the  microscope,  in 
lozenge-shaped  crystals,  resembling  some  of  the  forms  of  uric  acid. 


URINARY    CALCULI.  153 

SECTION  III. 
Urate  (or  Lithate)  of  Ammonia  (NlI4O,HO,C10HaN404). 

374.  It  is  not  often  that  we  meet  with  calculi  composed 
wholly  of  urate  of  ammonia,  that  substance  being  more 
commonly  found  alternating  with  uric  acid,  earthy  phos- 
phates, or  other  matters.      These  calculi  are  generally 
small  in  size,  smooth,  or  slightly  tuberculated  (Fig.  57), 
and  pale  slate  or  clay  color,  some- 
times inclining  to  brown.     The  Fig.  57. 
concentric    layers     are     usually 

thinner,  and  less  distinctly  mark- 
ed, than  those  of  uric  acid. 

375.  When    heated,   urate    of 
ammonia     usually    decrepitates, 
gradually    disappears,*   and     in 
other  respects  behaves  like  uric 

acid  (369).    It  dissolves  tolerably      Urate  of  Ammonia  calculus, 
well  in  hot  water  ;    but  being  in- 
soluble, or  nearly  so,  in  cold,  is  deposited  again  when  the 
solution  cools,  as  an  amorphous  precipitate.     If  a  dilute 
acid,  as  hydrochloric,  be  added  to  a  hot  solution  of  urate 
of  ammonia,  the  latter  is  decomposed,  and  the  uric  acid 
set  free,  which,  being  sparingly  soluble  even  in  hot  water, 
is  precipitated  in  the  form  of  minute  crystals  (Fig.  3,  page 
32). 

376.  "With  nitric  acid  and  ammonia,  urate  of  ammonia 
produces  the  same  results  as  uric  acid  (371). 

377.  Urate  of  ammonia  dissolves  readily  in  a  warm 
dilute  solution  of  potash,  giving  off  at  the  same  time 
ammoniacal  fumes  by  which  it  may  be  distinguished  from 
uric  acid  and  urate  of  soda.     The  addition  of  a  dilute 
acid  to  the  hot  solution  causes  a  crystalline  precipitate  of 
uric  acid  (373). 

SECTION  IV. 
Phosphate  of  Lime  (3CaO,PO5). 

378.  Calculi  of  phosphate  of  lime  are  most  commonly 
smooth  and  even  polished  on  the  surface.  The  concentric 


154  URINARY    CALCULI. 

laminae  are  generally  arranged  with 
considerable  regularity  (Fig.  58) ; 
and  when  the  calculus  is  broken, 
these  separate  from  each  other 
with  great  facility,  forming  de- 
tached crusts.  The  color  is  usually 
fawn  or  stone  color. 

Phosphate  of  Lime  Calculus.  orrn       T>    &  ^i          11  •  "A 

379.    Before   the    blowpipe   it 
chars,  owing  to  the  presence  of  a 

little  animal  matter,  and  gradually  becomes  white  as  the 
carbonaceous  matter  burns  away.  It  is  almost  infusible, 
requiring  for  its  fusion  so  intense  and  prolonged  a  heat, 
that  few  can  succeed  in  fusing  it. 

380.  The  residue,  after  ignition,  is  neutral  to  test-paper. 

381.  It  is  soluble,  without  effervescence,  in  dilute  nitric 
or  hydrochloric. acid  (49). 

382.  To  the  solution  in  nitric  acid  formed  in  the  last 
experiment  add  ammonia  in  slight  excess ;  the  phosphate 
of  lime  will  be  precipitated  as  a  gelatinous  precipitate. 
Ee-dissolve  this   in  a  little  acetic  acid,  and  divide  the 
solution  into  two  parts. 

383.  To  one  part  of  the  acetic  solution  add  a  drop  of 
perchloride  of  iron,  which  will  cause  a  yellowish  white 
precipitate  of  perphosphate  of  iron  (Fe2O3,P05). 

384.  To  the  second  part  of  the  solution  add  oxalate  of 
ammonia,  when  the  white  precipitate  of  oxalate  of  lime 
will  be  formed. 

385.  If  a  little  of  the  powdered  phosphate  of  lime  be 
mixed  with  about  twice  its  bulk  of  the  double  phosphate 
of  ammonia  and  magnesia,  or  triple  phosphate  (MgO,N 
H4O,HO,P05),  and  heated  before  the  blowpipe  on  platinum 
wire,  it  readily  fuses.     The  fusible  calculus  is  composed 
of  a  similar  mixture  of  the  two  salts  (391). 

SECTION  V. 

Phosphate  of  Ammonia  and  Magnesia,  or  Triple  Phosphate 
(MgO,NH40,HO,POB). 

386.  Calculi   composed  entirely  of  triple   phosphate 
are  of  somewhat  rare  occurrence  ;  but  mixed,  or  alternat- 
ing with  other  matters,  and  indeed  constituting  the  great 


URINARY    CALCULI.  155 

bulk  of  the  concretion,  this  substance  is  very  common. 
Such  calculi  are  sometimes  found  to  have  been  deposited 
in  concentric  layers,  and  sometimes  consist  of  an  aggre- 
gated mass  of  prismatic  crystals.  They  are  usually 
nearly  colorless,  or  slightly  tinged  with  drab  or  stone 
color.  The  surface  is  most  commonly  rough  and  uneven, 
and  often  covered  with  small,  shining  crystals. 

387.  The  triple  phosphate  calculus,  when  heated  before 
the  blowpipe,  chars,  and  gives  -off  the  smell  of  ammonia  ; 
swells  up,  gradually  becomes  gray  as  the  carbonaceous 
matter  is  consumed,  and  ultimately  fuses. 

388.  It  is  almost  insoluble  in  water,  but  if  boiled,  a 
small  quantity  will  be  found  to  dissolve. 

389.  It  dissolves  readily  in  dilute  hydrochloric  and 
most  other  acids,  and  is  again  thrown  down  in  the  form 
of  a  crystalline  precipitate,  when  the  solution  is  neutral- 
ized with  ammonia.     If  the  precipitate  thus  obtained  be 
examined  under  the  microscope,  it  will  be  found  to  con- 
sist of  well-defined  crystals,  which,  if  the  solution  has 
been  supersaturated  with  the  ammonia,  are  stellate  (Fig. 
10,  page  46)  ;  but  if  merely  neutralized,  they  are  pris- 
matic (Fig.  8,  page  45)  (44). 

390.  When   heated  with  a  solution  of  potash,  it  is 
decomposed,  the  potash  combining  with  the  phosphoric 
acid,  and  setting  free  the  ammonia  and  the  magnesia. 
The  former  volatilizes,  and  may  be  detected  by  the  smell, 
while  the  magnesia  is  precipitated  (49). 

MgO,NH40,HO,P05  +  1KO  =  2KO,HO,PO&  +  NH3  +  MgO,HO. 


SECTION  VI. 


Fusible   Calculus,  which  is  a  mixture  of  Phosphate  of  Lime 
(3CaO,P05),  and  the  Triple  Phosphate  (MgO,NH4O,HO, 


391.  The  fusible  matter  of  which  this  form  of  calculus 
is  composed,  is,  next  to  uric  acid,  the  most  common  of 
the  ingredients  of  calculi.  It  sometimes  constitutes  the 
entire  mass  of  the  calculus;  is  also  frequently  found  alter- 
nating with  other  ingredients;  and  very  commonly  forms 
the  outer  crust  of  calculi  composed  of  uric  acid  and  other 


156 


URINARY    CALCULI. 


matters.     Fusible  calculi  are  generally  oval  and  irregu- 
lar in  form  (Fig.  59);  white,  soft,  and 
Fig-  59.  friable,  resembling  chalk;  though  oc- 

casionally they  are  compact  and  hard. 
392.  This  calculus  is  chiefly  charac- 
terized by  the  readiness  with  which 
it  fuses  before   the   blowpipe,  with- 
out being  consumed ;  in   which   re- 
Fusibie  calculus.          spect  it  differs  from  all  other  kinds 
of  calculus.     During  the  ignition,  the 
ammonia  and  water  are  expelled,  leaving  a  mixture  of 
the  phosphates  of  lime  and  magnesia. 

393.  If  a  portion  of  the  calculus  be  dissolved  in  dilute 
hydrochloric  acid,  and  ammonia  added  in  slight  excess, 
the  mixed  phosphates  are  precipitated  and  may  be  recog- 
nized under  the  microscope  (43). 

394.  If  the  precipitate  be  redissolved  in  acetic  acid, 
and  the  solution  mixed  with  oxalate  of  ammonia,  the 
lime  will  be  separated  as  oxalate,  and  if  this  be  filtered 
off  (after  boiling),  the  phosphate  of  magnesia  and  arnrno- 
nia  may  be  obtained  as  a  crystalline  precipitate  by  adding 
an  excess  of  ammonia. 


SECTION  VII. 
Oxalate  of  Lime  Calculus  (CaO,C203)« 

395.  Calculi  are  not  unfrequently  met  with,  composed 
almost  entirely  of  oxalate  of  lime ;  but  more  commonly 
the  nucleus  will  be  found  to  con- 
Fig.  60.  sist  of  uric  acid  or  urate  of  lime. 
Oxalate  of  lime  calculi  are  usually 
very  dark  in  color,  either  brown  or 
dark  olive,  or  a  kind  of  dirty  pur- 
ple.    Their  surface  is  much  more 
irregular  and  rugged  than  that  of 
other  descriptions  of  calculi :  attd 
when  sawn  asunder,  they  exhibit 
an  irregular  and  angular  structure, 
as  shown  in  Fig.  60.     From  their 
resemblance  to  the  fruit  of  the  mulberry,  this  variety  is 
commonly  known  as  the  mulberry  calculus. 


Oxalate  of  Lime  Calculus. 


URINARY    CALCULI.  157 

396.  There  is  also  another  form  in  which  oxalate  of 
lime  calculi  are  occasionally  met  with,  commonly  called 
hemp-seed  calculi.     These  are  small,  round,  or  oval,  and 
very  smooth  and  polished  on  the  exterior;  they  generally 
contain  also  a  little  urate  of  ammonia. 

The  general  form  and  appearance  of  these  oxalate  of 
lime  calculi  are  usually  so  peculiar  and  characteristic, 
that  they  may  be,  in  most  cases,  easily  recognized  by 
simple  inspection. 

397.  Powdered  oxalate  of  lime  dissolves  without  effer- 
vescence in  dilute  nitric  and  hydrochloric  acids,  and  is 
again  thrown  down  unchanged,  in  the  form  of  a  white 
precipitate,  when  the  acid  solution  is  neutralized  with 
ammonia;  the  precipitate   is    insoluble  in   acetic   acid. 
Occasionally  a  little  carbonate  of  lime  is  found  mixed 
with  the  oxalate,  in  which  case  slight  effervescence  will, 
of  course,  take  place  on  the  addition  of  the  acid. 

398.  Oxalate  of  lime  is  insoluble  in  acetic  and  oxalic 
acids. 

3j)9.  When  heated,  it  blackens,  and  gives  off  a  disa- 
greeable smell,  resembling  that  of  burnt  feathers.  If  the 
heat  be  continued  a  short  time,  the  residue  becomes 
white,  and  then  consists  of  carbonate  of  lime,  into  which 
the  oxalate  is  converted ;  carbonic  acid  being  also,  with 
other  gaseous  matters,  at  the  same  time  given  off. 

CaO,C203  4-  0  =  CaO,C02  -f-  C02. 

400.  Treat  the  residue  formed  in  the  last  experiment, 
with  dilute  hydrochloric  acid  :  it  readily  dissolves,  with 
effervescence,  showing  that  it  has  been  changed  into  the 
carbonate. 

401.  The  solution  of  chloride  of  calcium  (CaCT)  thus 
formed,  may  be  neutralized  with  ammonia,  and  tested  for 
lime  with  oxalate  of  ammonia,  which  will  throw  down 
the  oxalate  of  lime  (CaO,C2O3-f2Aq),  in  the  form  of  a 
white  precipitate  (171). 

402.  If  the  oxalate  of  lime  be  kept  intensely  heated 
for  some  little  time,  the  carbonate  which  is  at  first  formed 
is  reduced  to  the  state  of  caustic  lime  (CaO) ;  which  rnay 
be  proved  by  placing  the  residue,  when  cold,  on  a  piece 

14 


153  URINARY    CALCULI. 

of  moistened  turmeric  paper,  the  yellow  color  of  which 
will  be  turned  to  brown. 

SECTION  VIII. 
Urate  (or  Lithate)  of  Lime  (CaO,HO,C10H2N404). 

403.  This  substance,  though  never  found  composing 
entire  calculi,  is  not  unfrequently  present  in  small  quan- 
tities in  concretions  which  consist  chiefly  of  uric  acid, 
oxalate  of  lime,  or  other  matters. 

404.  Urate  of  lime  is  nearly  insoluble  in  cold  water, 
but  dissolves  in  hot,  though  somewhat  less  readily  than 
urate  of  ammonia  (375).     The  hot  aqueous  solution  de- 
posits it  again  on  cooling,  generally  in  the  form  of  minute 
needle-shaped  crystals. 

405.  Like  the  other  urates,  it  is  decomposed  by  hydro- 
chloric acid.     If  the  acid  be  added  to  a  hot  aqueous  solu- 
tion of  the  salt,  a  crystalline  precipitate  of  uric  acid  is 
thrown  down  (377,  373),  and  chloride  of  calcium  remains 
in  solution. 

406.  When  tested  with  nitric  acid  and  ammonia,  in 
the  manner  described  in  paragraph  371,  urate  of  lime 
behaves  like  uric  acid  and  the  other  urates,  yielding  the 
rich  purple  color  of  murexide. 

407.  As  this  is  the  only  salt  of  lime  found  in  calculi 
which  is  soluble  in  hot  water,  it  may  be  supposed  to  be 
present  when,  after  boiling  a  little  of  the  powdered  cal- 
culus in  water,  the  Jwt  aqueous  solution  gives  a  white 
precipitate  of  oxalate  of  lime  (CaO,C2O3+2Aq),   when 
tested  with  oxalate  of  ammonia. 

SECTION  IX. 
Cystine  (C6H6N04S2). 

408.  Calculi  of  cystine  are  of  rather  rare  occurrence. 
They  are  usually  more  or  less  crystalline  in  structure, 
not  deposited  in  laminae,  soft,  and  of  a  pale  brownish- 
yellow  or  greenish  tint.     Small  calculi  composed  almost 
exclusively   of  this  substance   have   been    occasionally 
found  in  the  dog. 

409.  The  chemical  characters  of  cystine,  and  the  me- 


ANALYSIS    OF    CALCULI.  159 

thods  of  distinguishing  it  by  tests,  will  be  found  described 
in  the  chapters  on  urine  (172,  269,  &c.) 

410.  The  following  directions  will  facilitate  the  identi- 
fication of  the  several  varieties  of  urinary  calculi. 


CHAPTER  II. 

QUALITATIVE   EXAMINATION   OF  URINARY   CALCULI,    THE 
COMPOSITION  OF  WHICH  IS  UNKNOWN. 

411.  WHEN  a  calculus  has  to  be  examined  with  a  view 
to  ascertaining  the  nature  of  its  ingredients,  a  very  few 
simple  experiments,  conducted  on  some  such  plan  as  the 
following,  will  generally  furnish  the  required  informa- 
tion.    The  calculus  should  first  be  sawn  through,  and  the 
loose  dust  gently  brushed  away.     If  the  several  laminao 
of  which  the  mass  is  composed  appear  to  be  homogene- 
ous, and  to  consist  of  the  same  kind  of  matter,  a  small 
fragment  may  be  taken  from  any  part  of  it  for  examina- 
tion (412);  but  if,  as  is  more  frequently  the  case,  there 
appear  to  be  two  or  more  different  kinds  of  matter  con- 
tained in  the  several  layers  (367),  fragments  of  each  of 
them  should  be  carefully  detached  from  the  mass,  and 
examined  separately  in  the  following  manner. 

412.  Place  a  small  fragment  on  platinum  foil,  and  heat 
it  to  redness  before  the  blowpipe,  until  the  blackness  of 
the  charred  animal  matter  disappears.  Observe  whether — 

(a)  IT   BURNS   AWAY,  LEAVING   ONLY  A   MINUTE  TRACE 

OF  ASH  (413);  or 

(b)  IT  PROVES   INCOMBUSTIBLE,  WITHOUT   MATERIALLY 
LESSENING  IN  BULK  (414)  ;   or 

(c)  IT  is  PARTIALLY  CONSUMED,  leaving,  however,  a 
considerable  residue  of  incombustible  matter  (415). 

413.  IF  IT  BURNS  AWAY,  leaving  only  a  minute  trace 
of  incombustible  ash,  it  is  probably  either    uric   acid, 
urate  of  ammonia,  or  cystine ;  or  possibly  a  mixture  of 
two  or  more  of  them.     See  416 — 419. 

414.  IF  IT  is  INCOMBUSTIBLE,  not  materially  lessening 


160  ANALYSIS    OF    CALCULI. 

in  bulk  during  the  ignition,  it  is  probably  either  phos- 
phate of  lime,  triple  phosphate,  fusible  matter  (391), 
oxalate  of  lime  (converted  into  carbonate  by  the  heat), 
urate  of  lime  (also  converted  into  carbonate) ;  or,  perhaps, 
two  or  more  of  those  substances  mixed  together.  See 
420—425. 

415.  IF  THE  FRAGMENT  IS  PARTIALLY  CONSUMED,  it  will 

probably  be  found  to  consist  of  a  mixture  of  one  or  more 
of  the  combustible  substances  mentioned  in  paragraph 
413,  with  some  of  those  enumerated  in  paragraph  414. 
See  426—428. 

Examination  of  Combustible  Calculi  (413). 

416.  If  the  calculus  (in  powder)  is  found  to  be  spar- 
ingly  SOLUBLE   IN    WARM  WATER;   SOLUBLE    IN    DILUTE 

SOLUTION  OF  POTASH,  without  the  evolution  of  ammonia; 
and  to  form,  when  tested  with  nitric  acid  and  ammonia, 
a  PURPLE  RESIDUE  ;  it  is  probably  URIC  ACID  (370,  372, 
371).  (Confirm  373.) 

417.  If  it  is  found  to  be  SOLUBLE  IN  HOT  WATER; 

SOLUBLE  IN  DILUTE  SOLUTION   OF  POTASH,  with  the  6VO- 

lution  of  ammoniacal  vapors;  and  to  yield,  with  nitric 
acid  and  ammonia,  a  PURPLE  RESIDUE  ;  it  is  probably 
URATE  OF  AMMONIA  (375,  377,  376).  (Confirm  373.) 

418.  If  it  is  found  to  be  INSOLUBLE  IN  WARM  WATER  ; 
readily  SOLUBLE  IN  AMMONIA  ;  the  ammoniacal  solution 
yielding,  on  slow  evaporation,  HEXAGONAL  CRYSTALLINE 
PLATES,  it  is  probably  CYSTINE  (174,  173).  (Confirm  174, 
271,  273). 

419.  If  it  is  suspected  that  more  than  one  of  the  above 
substances  are  present,  a  little  of  the  powder  may  be 
boiled  with  water,  and  if  any  portion   remains  undis- 
solved,  the  mixture  filtered  while  hot. 

(a)  If  the  clear  filtered  liquid  DEPOSITS  ON  COOLING, 

AN  AMORPHOUS  PRECIPITATE,  URATE  OF  AMMONIA  IS  prob- 
ably present  (375).  (Confirm  417.) 

(b)  If  the   insoluble  portion  gives  a   PURPLE   COLOR 
when  tested  with  nitric  acid  and  ammonia,  URIC  ACID  is 
probably  present  (371).     (Confirm  416.) 

(c)  If  the   insoluble   portion   is  wholly   or   partially 


ANALYSIS    OF    CALCULI.  161 

SOLUBLE  IN  AMMONIA:  the  ammoniacal  solution,  yielding 
on  evaporation,  HEXAGONAL  PLATES,  CYSTINE  is  probably 
present  (173).* 

Examination  of  Incombustible  Calculi  (414). 

420.  If  the  matter  of  the  calculus  is  INFUSIBLE  BEFORE 
THE  BLOWPIPE;  SOLUBLE  IN  DILUTE  HYDROCHLORIC  ACID  ; 
the  acid  solution  of  the  substance  after  ignition,  yielding, 
when  neutralized  with  ammonia,  an  AMORPHOUS  PRECIPI- 
TATE, it  is  probably  PHOSPHATE  OF  LIME  (379,  381,  382). 
(Confirm  383,  384) 

421.  If  it  is  TOLERABLY  FUSIBLE  before  the  blowpipe ; 

SOLUBLE  IN  DILUTE  HYDROCHLORIC  ACID ;    the    acid   SOlu- 

tion  giving,  when  neutralized  with  ammonia,  a  CRYSTAL- 
LINE PRECIPITATE,  it  is  probably  TRIPLE  PHOSPHATE 
(387,  389).  (Confirm  390.) 

422.  If  it  is   readily  FUSIBLE   before  the   blowpipe; 

SOLUBLE  IN  DILUTE  HYDROCHLORIC  ACID;    the   acid   SOlu- 

tion  yielding,  when  supersaturated  WITH  AMMONIA,  A 
PRECIPITATE,  which,  when  examined  under  the  micro- 
scope, is  found  to  contain  both  AMORPHOUS  PARTICLES 
and  also  CRYSTALLINE  STELL^E,  it  is  probably  composed 

Of  the  MIXED  OR  FUSIBLE  PHOSPHATES  (392,  394). 

423.  If  the  substance,  before  ignition,  is  SOLUBLE  WITH- 
OUT EFFERVESCENCE  in  dilute  hydrochloric  acid;  the  acid 
solution  yielding  a  WHITE  PRECIPITATE  WHEN  NEUTRAL- 
IZED WITH  AMMONIA;  and  after  gentle  ignition,  is  SOLUBLE 
WITH  EFFERVESCENCE  in  the  dilute  acid;  the  acid  solu- 
tion, moderately  diluted,  now  yielding  NO  PRECIPITATE 
when  neutralized  with  ammonia,  it  is  probably  OXALATE 
OF  LIME  (397,  400,  401).    (Confirm  398,  402.) 

424.  If  the  hot  aqueous  solution,  formed  by  boiling  a 
little  of  the  powdered  calculus  with  water,  gives  a  WHITE 

PRECIPITATE  WITH   OXALATE   OF   AMMONIA,  the    presence 

of  URATE  OF  LIME  is  indicated  (407).  (Confirm  404,  405, 
406.) 

*  A  very  rare  combustible  calculus,  discovered  by  Heller,  is  called 
urostealith.  It  is  soft  and  elastic  when  fresh,  but  becomes  hard  after 
drying.  When  heated  it  evolves  a  resinous  odor,  somewhat  similar 
to  that  of  benzoin.  It  is  readily  soluble  in  ether,  and  sparingly  in 
alcohol. 

14* 


162  ANALYSIS    OF    CALCULI. 

425.  If  it  is  suspected  that  more  than  one  of  the  above 
substances  are  present  in  the  portion   of  the  calculus 
under  examination,  it  may  be  gently  ignited,  and  then 
treated  with  dilute  hydrochloric  acid. 

(a)  IF  EFFERVESCENCE  ENSUES  (the  calculus  before  igni- 
tion, not  causing  effervescence  with  the  acid),  oxalate  (or 
possibly  urate  (c),)  of  lime  is  present  (397,  400). 

(6)  Supersaturate  the  acid  solution  with  ammonia;  and 
if  any  PRECIPITATE  is  PRODUCED,  examine  it  under  the 
microscope  for  PHOSPHATE  OF  LIME  and  TRIPLE  PHOS- 
PHATE (382,  389). 

(c)  Boil  a  little  of  the  powdered  calculus  with  water; 
and  test  the  hot  aqueous  solution  thus  obtained,  with 
oxalate  of  ammonia.  If  a  WHITE  PRECIPITATE  is  pro- 
duced, URATE  OF  LIME  is  probably  present  (407).  (Con- 
firm 405.) 

Examination  of  Partially  Combustible  Calculi  (415). 

426.  When  the  calculus,  or  any  portion  of  it,  is  found 
to  be  partially  consumed  when  ignited,  it  is  probably  a 
mixture  of  one  or  more   of  the   combustible   matters 
enumerated  in  paragraph  413,  associated  with  one   or 
more   of  the   incombustible   ingredients   mentioned   in 
paragraph  414. 

427.  A  portion  of  the  calculus,  before  ignition,  may 
first  be  examined  for  the  organic  or  combustible  ingre- 
dients, in  the  manner  described  in  paragraph  419,  a,  £>, 
and  c. 

428.  Another  portion  of  the   calculus  may  then   be 
gently  ignited  on  platinum  foil,  and  the  residue  examined 
for  the  inorganic  matters,  according   to  the   directions 
given  in  paragraph  425,  a,  &,  and  c. 


BILIARY   CALCULI    OR    GALL-STONES.          163 


CHAPTER  III. 

BILIARY  CALCULI  OR  GALL-STONES. 

429.  BILIARY  calculi  are  usually  of  a  pale  yellow  or 
brownish   color;    soft,  soapy  to   the   touch,  and    easily 
crushed  into  small  fragments  by  pressure;  and  the  tex- 
ture of  the  mass  is  in  most  cases  decidedly  crystalline. 
The   size  most   commonly    met  with  is 

about  that  of  a  pea;  but  they  are  frequently  Fi8-  61- 

found  much  smaller,  and  occasionally 
almost  as  large  as  a  pigeon's  egg.  The 
form  is  generally  irregular  and  some- 
what  angular,  as  shown  in  Fig.  61. 

430.  They  usually  contain  from  fifty 

to  eighty  per  cent,  of  cholesterin  (C52H44       Binary  calculi. 
02);    the   rest   of  the   concretion   being 
made  up  of  biliary  resin   and  coloring  matter,  mucus, 
and  traces  of  other  animal  matters,*  with  a  small  quantity 
of  inorganic  salts.     The  percentage  composition  of  three 
specimens  analyzed  by  Brande  was  as  follows: — 

i.  ii.  in. 

Cholesterin     .         .         .        .81-25         69-76  81-77 

Biliary  resin  ....     3-12           5-66  3-83 

Bile-pigment  .         .         .         .9-38        11-38  7-57 
Albumen  and  salts  extractable 

by  water     .... 3-83 

Biliary  mucus         .         .         .6-25        13-20 

431.  Heat  a  small  fragment  of  gall-stone  on  platinum 
foil;  it  will  fuse  and  burn  with  a  bright.but  smoky  flame, 
leaving  a  small  fixed  residue,  consisting  of  inorganic  salts. 

432.  When  coarsely  powdered,  it  dissolves  readily  in 
boiling  alcohol;  and  on  cooling,  the  cholesterin  crystal- 
lizes  out  in  the  form    of  fine  scaly  crystals.  (Fig.  62), 

*  Among  which  stearate  and  palmitate  of  lime  have  been  noticed. 


IfU 


GOUTY    CONCKETIONS. 


62- 


while  the  biliary  resinous  and  coloring  matters  remain 
in  solution,  giving  the  liquid  a  yellowish  tinge. 

433.  It  is  insoluble  in  dilute  nitric  and  hydrochloric 
acids.     It  is  insoluble  also  in  a  solution  of  potash;  thus 

differing  from  other  fatty 
and  oily  substances, 
which  cholesterin  re- 
sembles in  many  parts. 

Cholesterin  is  found  in 
large  quantity  in  the 
fluid  in  ovarian  dropsy, 
and  in  hydrocele. 

434.  For  a  more  com- 
plete analysis  of  biliary 
calculi,  Dr.  Thudichum* 
recommends  the  follow- 

ing process  :  The  powdered  calculus  is  digested  with  hot 
benzole,  which  dissolves  the  cholesterin.  The  residue, 
having  been  washed  with  alcohol,  and  dried,  is  treated  with 
ether  and  a  little  nitric  acid,  by  which  the  fatty  acids  are 
removed.  On  washing  the  residue  on  the  filter  with 
water,  phosphates  and  nitrates  of  lime  and  magnesia  are 
extracted  (with  occasionally  a  little  copper).  The  final 
residue  consists  of  biliary  coloring  matter,  and  a  small 
quantity  of  earthy  salts. 


CHAPTER  IV. 

GOUTY   CONCKETIONS. 

435.  THESE  earthy  concretions,  which  form  in  the  joints 
of  gouty  persons,  are  usually  white,  or  nearly  so,  soft 
and  friable,  closely  resembling  chalk  in  appearance,  and 
hence  commonly  known  as  cJialk  stones.  They  seem  to 
vary  a  good  deal  in  composition  ;  but  in  the  great  majority 
of  those  which  have  been  analyzed,  acid  urate  of  soda 


*  Chern.  Soc.  Qtiar.  Journ.,  July,  1861. 


QOUTY    CONCRETION'S.  105 

^OJ  appears  to  form  the  principal  and 
most  characteristic  ingredient.  They  contain  also  a  con- 
siderable quantity  of  chloride  of  sodium  and  dried  cellular 
tissue;  with  occasionally  urate  of  lime  (CaO,HO,C10H2N4 
OJ,  phosphate  of  lime  (3CaO,PO.),and  chloride  of  potas- 
sium. The  presence  of  a  large  quantity  of  uric  acid 
may  be  shown  by  the  formation  of  the  purple-colored 
murexide,  when  a  little  of  the  concretion,  in  powder,  is 
treated  with  nitric  acid  and  ammonia,  in  the  manner 
described  in  paragraph  371. 

Qualitative  Examination  of  Gouty  Concretions. 

436.  Eeduce  the  concretion  intended  for  analysis  to 
tolerably  fine  powder,  and  digest   it   in  cold   water  to 
dissolve  out  the   chlorides   of  sodium   and   potassium. 
Filter  the  solution  from   the  insoluble  portion,  which 
must  be  reserved  for  subsequent  examination  (440). 

437.  Test  a  few  drops  of  the  aqueous  solution  thus 
formed  with  nitrate  of  silver.     A  white  curdy  precipitate, 
which  is  readily  soluble  in  ammonia,  but  insoluble  in 
nitric  acid,  will  show  the  presence  of  CHLORINE  (chloride 
of  potassium  or  sodium)  (41,  a). 

438.  Mix  the  rest  of  the  aqueous  solution  with  bichlo- 
ride of  platinum ;  evaporate  the  mixture  to  dryness,  or 
nearly  so,  on  a   water-bath ;   and   observe   the   yellow, 
needle-shaped  crystals  of  the  double  chloride  of  sodium 
and   platinum    (NaCl,PtCl2),  showing    the    presence   of 
SODIUM  (chloride  of  sodium). 

439.  Add  a  little  alcohol  to  the  evaporated  residue, 
and  observe  whether  any  small,  yellow,  sandy-looking 
crystals  remain  undissolved,  indicating  the  presence  of 
POTASSIUM  (41,  e). 

440.  The  portion  which  proved  insoluble  in  cold  water 
(436),  may  now  be  treated  with  hot  water,  and  gently 
boiled  with  successive  small  quantities  of  the  liquid  as 
anything  appears  to  dissolve.     The  urate  of  soda  is  thus 
slowly  dissolved,  together  with  any  urate  of  lime  that 
may  be  present  (97,  404).     The   matter  which  proves 
insoluble  in  the  hot  water  is  to  be  retained  for  subsequent 
examination  (444). 


166  GOUTY    CONCRETIONS. 

441.  Hydrochloric  acid  is  now  added  in  slight  excess 
to  the  hot  aqueous  solution,  and  the  mixture  set  aside 
until  it  cools,  in  order  to  allow  the  uric  acid,  which  will 
have  been  displaced  from  the  soda  and  lime  by  the  hydro- 
chloric acid  (405),  to  separate  completely  from  the  solution. 
The  uric  acid  is  thus  precipitated  ;  leaving  in  solution 
chloride  of  sodium,  and  also,  in  case  any  urate  of  lime 
was  present  in  the  concretion,  a  little  chloride  of  calcium. 

442.  The  mixture  thus  obtained  is  filtered.    The  URIC 
ACID  may  be  examined  with  the  microscope  and  with 
other  tests ;  (373,  371) ;  and  a  little  of  the  aqueous  solution 
may  be  neutralized  with  ammonia,  and  tested  for  LIME 
with  oxalate  of  ammonia  (171). 

443.  The  rest  of  the  aqueous  solution  may  be  evapo- 
rated at  a  gentle  heat  with  bichloride  of  platinum  ;  when 
the  yellow  needles  of  the  double  chloride  of  sodium  and 
platinum  will  prove  the  presence  of  a  large  quantity  of 
SODA  derived  from  the  urate  (435). 

444.  The  remaining  portion  of  the  concretion,  which 
resisted  the  action  of  the  hot  water  (440)  may  now  be 
examined.     It  will  probably  be  found  to  consist  chiefly 
of  dried  cellular  matter,  with  perhaps  a  little  phosphate 
of  lime  (435).     The  animal  matter  may  be  burnt  away, 
by  keeping  it  at  a  red  heat  until  the  blackness  disappears; 
after  which  the  incombustible  residue  may  be  examined 
in  the  manner  described  in  paragraph  425,  and  will  prob- 
ably be  found  to  consist  of  phosphate  of  lime. 

445.  The  following  is  an  analysis  by  T.  J.  Herapath  of 
some  concretions  taken  from  the  joints  of  the  fingers  of 
a  man  suffering  from  gout : — 

Fat  ...  .       1-123 

Chloride  of  sodium 


Phosphate  of  soda 

Extractive  matter 

Albumen  . 

Urate  of  soda,  with  some  urate  of  potash 

Urate  of  lime    . 


traces 


43-973 
14-769 


Phosphate  of  lime 34-141 

Perphosphate  of  iron traces 

Water  and  loss 5-994 

100-000 


SOLID    EXCREMENTS.  167 


CHAPTEK  V. 

SOLID  EXCREMENTS. 

445a.  THE  separation  of  the  proximate  principles  con- 
tained in  the  solid  excrements  is  effected  by  Dr.  Marcet, 
by  the  following  process : — 

The  feces  are  exhausted  by  boiling  alcohol,  and  rapidly 
strained  through  a  cloth.  The  alcoholic  solution,  on 
standing  for  a  short  time,  yields  a  deposit  which  is  partly 
dissolved  by  boiling  alcohol;  the  insoluble  portion  of 
this  deposit  is  boiled  with  potash,  which  dissolves  it 
almost  -entirely,  and  the  alkaline  solution,  neutralized 
with  hydrochloric  acid,  gives  a  deposit  of  margaric  acid, 
whilst  the  acid  filtrate,  neutralized  by  ammonia,  yields  a 
precipitate  of  phosphate  of  lime. 

The  alcoholic  solution,  after  longer  standing,  deposits 
some  margarate  of  magnesia,  and  if  exposed  to  cold  for 
some  hours,  it  gives  crystals  of  excretine. 

If  the  solution  obtained  by  boiling  the  first  deposit 
with  alcohol  be  evaporated  to  dryness,  the  residue  ex- 
tracted with  ether,  and  the  ethereal  solution  heated  with 
alcohol  and  lime-water,  a  precipitate  is  formed  which, 
when  treated  with  hydrochloric  acid  and  ether,  yields, 
on  evaporating  the  ethereal  solution,  an  olive  colored 
substance  named  excrctolic  acid. 

If  the  alcoholic  liquid  containing  the  excretine  (or  from 
which  the  excretine  has  been  separated  by  cooling)  be 
mixed  with  lime,  a  yellowish-brown  deposit  is  formed, 
which  yields  excretine  to  boiling  ether.  If  the  portion 
left  undissolved  by  ether  be  treated  with  alcohol  and 
hydrochloric  acid,  it  gives  a  port-wine  colored  solution, 
which  deposits  margaric  acid  on  standing.  If  water  be 
then  added,  and  the  solution  concentrated  by  evaporation, 
a  brown  substance  separates,  which  may  be  purified  by 


168  SOLID    EXCREMENTS. 

solution  in  ether  and  washing  with  water.  It  then  much 
resembles  the  coloring  matter  of  blood  and  that  extracted 
by  Dr.  Harley  from  urine  (36). 

Excretine  (C78H78O2S).  This  new  proximate  principle 
crystallizes  in  four-sided  prisms,  which  are  insoluble  in 
water,  and  sparingly  soluble  in  cold  alcohol,  but  dissolve 
readily  in  ether.  Its  solution  has  a  feeble  alkaline  reac- 
tion. It  fuses  a  little  below  212°,  and  is  not  dissolved 
by  boiling  with  solution  of  potash. 

Excretolic  acid,  the  composition  of  which  has  not  yet 
been  determined,  is  a  very  fusible  olive-colored  body, 
which  is  insoluble  in  water  and  in  boiling  potash,  dis- 
solves sparingly  in  cold  alcohol,  but  readily  on  heating, 
and  is  very  soluble  in  ether.  Its  solutions  have  a  marked 
acid  reaction. 

As  far  as  they  have  yet  been  examined,  healthy 
human  excrements  contain — 

Excretine.* 

Excretolic  acid. 

Peculiar  red  coloring  matter. 

Margarates  of  lime  and  magnesia. 

Butyric  acid. 

Taurine. 

Phosphate  of  lime. 

Phosphate  of  magnesia  and  ammonia. 

Phosphate  of  potash. 

Insohible  and  undigested  matters  derived  from  the  food. 

*  Dr.  Marcet  estimates  the  average  amount  of  excretine  in  each 
evacuation  at  about  2'8  grs.  In  the  feces  of  an  infant  cholesterine 
was  found,  but  no  excretine.  The  feces  of  a  man  with  a  diseased 
pancreas  contained  a  large  proportion  of  bistearate  of  soda. 


PART  III. 

BLOOD. 
CHAPTER    I. 

HEALTHY    BLOOD. 


SECTION   I. 
General  Characters  of  Blood. 

446.  THE  general  appearance  of  blood,  as  it  flows  from 
the  vessels  through  which  it  circulates  in  the  living  body, 
is  familiar  to  every  one,  as  an  opaque,  slightly  viscous 
fluid,  of  a  more  or  less  brilliant  red  color;  that  from  the 
arteries  being  brighter  and  more  scarlet  than  that  from 
the  veins.     It  has,  while  warm,  a  faint  though  character- 
istic odor,  differing  in  the  blood  of  different  animals,  and 
a  saline  and  disagreeable  taste.     The  specific  gravity  of 
healthy  blood  appears  to  vary  from  1050  to  1058,  the 
average  being  about  1055.     It  is  always  alkaline**  to 
test-paper,  from  the  presence  of  an  alkaline  carbonate. 

447.  While  circulating  in  the  vessels,  tlood  consists 
of  a  nearly  colorless  and  transparent  liquid,  in  which 
float  myriads  of  minute  vesicular  bodies  or  corpuscles, 
of  which  by  far  the  greater  number  are  of  a  bright  red 
color ;  and  these,  being  so  small  as  to  be  individually 
quite  invisible  without  the  aid  of  a  tolerably  good  micro- 
scope, give  the  blood,  when  seen  with  the  naked  eye,  the 
appearance  of  being  a  homogeneous  red  fluid  (451).     A 
few  of  the  corpuscle's  are  colorless,  and  differ  also  in  other 

*  In  certain  morbid  conditions  an  acid  reaction  has  been  observed 
in  the  blood,  due,  it  is  said,  to  the  presence  of  free  lactic  acid. 

15 


170     GENERAL  CHARACTERS  OF  BLOOD. 

respects  from  the  red  ones  (464).  The  fluid  portion  of 
the  blood,  in  which  the  corpuscles  float,  is  usually  called 
the  liquor  sanguinis. 

448.  The  most  remarkable   peculiarity  presented  by 
the  blood  is  the  spontaneous  coagulation  which  it  begins 
to  undergo  almost  immediately  after  being  drawn,  gra- 
dually separating  into  a  more  or  less  firm  and  solid  red 
coagulum  or  clot,  consisting  of  coagulated  fibrin  mixed 
with  the  corpuscles,  and  a  pale  yellowish,  transparent, 
watery  liquid,  called  the  serwm,  holding  in  solution  all 
the  other  solid  matters  of  the  blood.     The  nature  and 
cause  of  this  phenomenon  will  be  more  fully  explained 
further  on  (473).     The  specific  gravity  of  the  serum  is 
lower  than  that  of  the  entire  blood,  being  about  1029. 

449.  The  chemical  composition  of  the  blood  is  highly 
complex ;  and  though  the  nature  of  the  principal  ingre- 
dients is  now  tolerably  well  understood,  our  knowledge 
of  the  more  obscure  parts  of  its  history  is  still  very  im- 
perfect.    The  following  substances  appear  to  enter  into 
its  composition  (Simon),  and  probably  further  researches 
will  reveal  the  presence  of  other  compounds,  and,  per- 
haps, also  prove  the  non-existence  of  some  of  those  now 
included  in  the  list. 


Water, 

{Albumen, 

Fibrin, 

Globulin, 

Coloring  matters   .    •?  jj^mapSein 

Extractive  matters    i  Alcoho1  extractive  (containing  traces  of  urea), 

I      VVotGi*  fivtrQ  r»t  i  vr& 

I  water  extractive, 

r  Cholesterin, 

Serolin, 

Fatty  matters   .     .    • 

Margaric  acid, 

Oleic  acid, 

Red  and  white  solid  fats,  containing  phosphates, 

Oxide  of  iron, 

Albuminate  of  soda, 

Phosphates  of  lime,  magnesia,  and  soda, 

Saline  matters  .     .    • 

Sulphates  of  potash  and  soda, 
Carbonates  of  lime,  magnesia,  and  soda, 

Chlorides  of  sodium  and  potassium, 

j   Lactate,  urate,  and  probably  hippurate  of  soda, 

^  Oleate  and  margarate  of  soda, 

BLOOD  CORPUSCLES.  171 

{Oxygen, 
Nitrogen, 
Carbonic  acid, 
Sulphur, 
Phosphorus. 

450.  It  will,  however,  be  more  convenient  for  our  pre- 
sent purpose,  to  consider  the  constituents  of  the  blood  as 
arranged  in  the  following  manner,  the  more  important 
substances  only  being  placed  separately,  and  the  others 
being,  for  the  sake  of  simplicity,  grouped  together : — 

Water, 

Red  and  white  corpuscles, 

Albumen, 

Fibrin, 

Alcohol  extractive, 

Water  extractive, 

Oily  fats, 

Crystalline  or  solid  fats, 

Fixed  saline  matters. 

A  short  description  of  each  of  these  substances  and 
groups,  will  assist  in  rendering  the  subsequent  analytical 
operations,  both  qualitative  and  quantitative,  more  simple 
and  intelligible  to  the  student. 

SECTION  II. 
Blood-  Corpuscles. 

451.  If  freshly -.drawn  blood,  previous  to  coagulation, 
be  examined  under  the  microscope,  it  will  be  found  to 
consist  of  a  transparent   and   nearly  colorless  fluid,  in 
which   float   innumerable  minute,  circular,  disk-shaped 
bodies  or  corpuscles,  of  which  by  far  the  greater  number 
appear  of  a  pale   yellowish  color,  though  they  are  in 
reality  red ;  the  paleness  of  the  color  being  caused  by 
the  red  rays  from  each  of  the  corpuscles  being  spread 
over  so  large  a  surface.     It  is  to  these  corpuscles  that  the 
red  color  and  opacity  of  the  blood  are  due;  the  liquor 
sanguinis  or  fluid  portion  of  the  blood,  in  which  they 
float,  being  nearly  colorless  and  perfectly  transparent. 

452.  These  minute  bodies,  which,  when  the  blood  is 

*  These  gases  appear  to  be  contained,  at  least  chiefly,  in  the  blood- 
corpuscles  ;  the  serum  has  been  shown  to  have  very  little  power  of 
absorbing  gases. 


172 


BLOOD-CORPUSCLES. 


Fig.  63. 


Blood-Corpuscles  magnified  400 
diameters. 


first  drawn,  float  freely  in  the  liquor  sanguinis,  occasionally 
adhere  together,  forming  little  aggregations  resembling 
strings  of  beads  or  rolls  of  coin 
(Fig.  63);  this  arrangement,  how- 
ever, is  not  always  permanent; 
and  the  corpuscles  gradually  be- 
come again  disunited  and  scattered. 
The  tendency  to  aggregate  to- 
gether is  usually  greater  during 
the  inflammatory  state,  frequently 
causing  the  red  corpuscles  to  col- 
lect in  irregularly  shaped  masses, 
which  sink  more  rapidly  than 
when  they  are  detached  from  each 
other.  This  is  one  of  the  causes 

which  tend  to  produce  what  is  known  as  the  huffy  coat, 
which  was  formerly  supposed  to  be  always  indicative  of 
inflammation,  but  which  has  since  been  found  to  be 
formed  almost  whenever  the  fibrin,  from  whatever  cause, 
coagulates  more  slowly,  or  the  corpuscles  subside  more 
rapidly,  than  in  healthy  blood  (454,  473). 

453.  The  red  corpuscles  of  human  blood  have  an  aver- 
age diameter  of  about  goW 
of  an  inch.  They  are  nearly 
circular,  flattened  disks,  each 
being  slightly  depressed  and 
concave  in  the  centre;  their 
thickness  is  usually  about  one- 
fourth  or  one-fifth  of  their 
diameter  (Fig.  64).* 

454.  When,  owing  to  the 
solidification  of  the  fibrin,  the 

Blood-Corpuscles  magnified  400  dia-     ,,        n  ,  /At-ei\        i 

meters.  blood    coagulates    (478),   the 

corpuscles  gradually  become 

entangled  in  the  network  of  the  solidifying  clot,  which 
is,  in  consequence,  of  a  bright  red  color;  while  the  serum, 
or  defibrinated  liquor  sanguinis,  is  left  nearly  colorless  as 


Fig.  64. 


*  For  further  particulars  relative  to  the  structure  of  the  blood-cor- 
puscles, see  Todd  and  Bowman's  Physiological  Anatomy  and  Phy- 
siology of  Man. 


BLOOD-CORPUSCLES.  173 

the  clot  subsides.  In  consequence  of  the  corpuscles 
being  slightly  heavier  than  the  liquid  in  which  they  float, 
they  begin  very  slowly  to  subside  almost  immediately 
after  the  blood  is  drawn;  so  that  the  lower  portion  of 
the  clot  usually  contains  a  larger  proportion  of  them, 
and  has  consequently  a  deeper  color  than  the  upper. 
This  is  the  case  to  a  remarkable  extent  in  certain  morbid 
conditions  of  the  blood,  which  will  be  noticed  further  on 
(589). 

465.  The  red  corpuscles  appear  to  consist  of  delicate 
membranous  vesicles,  filled  with  the  red  fluid  to  which 
they  owe  their  peculiar  color,  which  fluid  is  supposed  to 
consist  of  a  coloring  matter  containing  a  considerable 
quantity  of  iron,  to  which  the  name  of  hasmatin  has  been 
given,  associated  with  a  protein  compound,  in  many 
respects  analogous  to  albumen,  and  called  globulin.  The 
inclosing  membrane,  which  is  highly  elastic,  appears  to 
be  composed  either  of  coagulated  fibrin  or  albumen,  or 
of  some  other  modification  of  protein  closely  allied  to 
them. 

456.  When  placed  in  solutions  of  different  densities, 
the  phenomena  of  endosmosis  and  exosmosis  presented 
by  the  corpuscles  are  very  curious  and  interesting,  and 
may  be  seen  with  great  facility  with  the  help  of  a  tolerable 
microscope.  As  long  as  the  fluid  in  which  they  float  is 
of  the  same  density  as  that  which  they  contain — such,  for 
instance,  as  the  liquor  sanrjuinis — the  corpuscles  experience 
little  or  no  change  of  form.  But  if  the  external  liquid 
is  less  dense  than  that  contained  in  the  corpuscles,  the 
latter  will  become  more  or  less  distended  and  globular, 
owing  to  the  lighter  fluid,  in  obedience  to  the  well-known 
laws  of  endosmosis,  passing  through  the  membranous 
vesicles  into  the  interior  more  rapidly  than  the  heavier 
fluid  within  can  pass  outwards.  If,  on  the  other  hand, 
the  external  liquid  be  more  dense  than  that  contained 
within  the  corpuscles,  the  contrary  effect  will  be  pro- 
duced, and  the  corpuscles  will  immediately  begin  to 
collapse  and  assume  a  wrinkled  appearance  (Fig.  65). 
This  change  of  form  not  unfrequently  takes  place  spon- 
taneously, while  a  drop  of  blood  placed  between  two 
surfaces  of  glass  is  being  examined  under  the  micro- 

15* 


174  BLOOD-CORPUSCLES. 

Fig-  65.  scope,   especially   near   the 

edges,  where,  owing  to  eva- 
poration, the  liquid  with 
which  the  corpuscles  are  in 
contact  gradually  becomes 
more  concentrated,  and  con- 


® 


®  $®  a 


8 


sequently  more  dense. 

457.  The  liquor  sanguinis, 
or  fluid  portion  of  the  blood, 
as   it    exists    in   the  living 
Blood-corp^td8iCaS^d>maguified      body,  and  before   it  under- 
goes coagulation,  appears  to 

possess  the  same  density  as  the  red  fluid  contained  in  the 
vesicles ;  so  that,  as  long  as  it  continues  so,  no  change 
takes  place  in  the  form  of  the  corpuscles.  When,  how- 
ever, the  fibrin  which  was  before  dissolved  in  the  liquor 
sanguinis,  has  coagulated,  the  resulting  serum  becomes 
less  dense,  in  consequence  of  its  holding  in  solution  a 
smaller  amount  of  solid  matter  (448).  The  effect  of  this 
upon  the  blood-corpuscles  is  to  cause  them,  when  in  con- 
tact with  the  serum  of  coagulated  blood,  gradually  to 
enlarge  in  size,  in  consequence  of  the  increased  rapidity 
with  which  the  less  dense  serum  enters  through  the  mem- 
branous integument. 

458.  If  the  red  corpuscles  be  brought  in  contact  with 
water,  the  change  is  extremely  rapid  ;  they  instantly  swell 
to  a  much  larger  size,  the  vesicles  becoming  less  and  less 
distinct,  until  at  length,  unless  the  quantity  of  water  is 
very  small,  they  almost  entirely  disappear. 

459.  When,  owing  to  the  action  of  water,  or  some 
other  liquid  of  comparatively  low  specific  gravity,  the 
corpuscles  have  become  distended,  they  may,  if  the  dis- 
tension has  not   been  allowed  to  go  too  far,  be  again 
brought  back  almost  to  their  original  size,  and  even  be 
made  to  assume  a  wrinkled  appearance,  by  bringing  them 
in  contact  with  a  tolerably  strong  solution  of  sugar,  or 
of  certain  salts,  as  chloride  of  sodium  or  chloride  of  am- 
monium. 

460.  The  corpuscles  readily  dissolve  in  a  solution  of 
potash,  ammonia,  acetic  acid,  and  some  other  fluids. 

461.  Although  we  are  unable  to  separate  the  corpuscles 


BLOOD  CORPUSCLES.  175 

from  the  blood  by  filtration,  since  they  pass  readily 
through  the  pores  of  the  filter,  it  is  found  that  when 
mixed  with  certain  strong  saline  solutions,  they  are  re- 
tained by  it.  A  solution  .of  sulphate  of  soda,  for  example, 
having  a  specific  gravity  of  about  1*13,  when  mixed  with 
the  blood,  effectually  prevents  the  passage  of  the  cor- 
puscles through  the  filter.  This  remarkable  property 
has  been  applied  by  Figuier  to  the  purposes  of  analysis 
(582)* 

462.  When  blood  is  allowed  to  dry  at  common  tem- 
peratures, and  is  subsequently  moistened,  even  after  the 
lapse  of  considerable  time,  with  some  liquid  having  a 
specific  gravity  similar  to  that  of  the  serum  (448),  the 
corpuscles  are  found  to  have  retained  their  characteristic 
form  and  appearance,  and  may  be  readily  distinguished 
under  the  microscope.    This  circumstance  has  been  inge- 
niously applied  for  the  purpose  of  solving  a  question 
which  in  some  medico-legal  inquiries  is  one  of  grave 
importance,  viz.,  whether  the  stains  found  on  clothing  or 
elsewhere  are  or  are  not  stains  of  blood. 

463.  For  this  purpose  the  stain  is  to  be  moistened, 
and  gently  rubbed  with  a  little  fresh  white  of  egg,  or 
some  other  fluid  having  a  specific  gravity  of  about  1030 
to  1050.     It  is  then  scraped  off,  and  a  little  of  the  mix- 
ture examined  under  the  microscope  with  a  tolerably 
high  power,  when,  if  the  stain  consisted  of  blood,  the 
characteristic  corpuscles  will,  in  most  cases,  be  distinctly 
visible. 

It  is,  of  course,  desirable  to  obtain  chemical  as  well  as 
microscopical  evidence  of  the  presence  of  blood  in  the 
stain  under  examination.  With  this  view,  the  stained 
material  should  be  soaked  in  a  little  water  for  an  hour  or 
two,  when,  unless  the  stain  be  of  long  standing,  a  portion 
of  the  blood  will  be  extracted,  imparting  a  dingy  reddish 
color  to  the  liquid,  to  which  the  following  tests  should 
then  be  applied: — 

(a)  Boil  a  portion  in  a  test-tube ;  a  dirty  red  coagulum 

*  According  to  Dumas,  oxygen  should  be  passed  through  the 
liquid  during  filtration,  and  solution  of  sulphate  of  soda  allowed  to 
drop  into  it,  in  order  to  prevent  the  obstruction  of  the  pores  of  the 
filter. 


176  BLOOD-CORPUSCLES. 

should  be  formed.  On  dissolving  this  in  boiling  potash, 
the  solution  should  be  green  by  transmitted  and  red  by 
reflected,  light. 

(b)  Chlorine- water  should  decolorize  the  liquid,  and 
produce  a  white  flocculent  precipitate. 

(c)  Nitric  acid  should  produce  a  brown  coagulum  of 
albumen  and  coloring  matter.    The  albumen  may  also  be 
tested  for  with  chloride  of  mercury,  and  with  acetic  acid 
and  ferrocyanide  of  potassium  (137,  138). 

(d)  Evaporate  the  remainder  of  the  solution  to  dryness, 
and  heat  the  residue,  observing  whether  the  offensive 
odor  of  burnt  blood  is  evolved.     Incinerate  the  residue 
completely,  and  boil  the  ash  with  a  few  drops  of  hydro- 
chloric acid ;  dilute  the  solution  with  water,  and  test  for 
iron  with  ferrocyanide  of  potassium. 

If  the  blood  has  not  been  extracted  by  soaking  in  wa- 
ter, the  piece  of  stuff  with  the  stain  should  be  placed  in 
a  stout  glass  tube,  closed  at  one  end,  about  half  an  inch 
in  diameter,  and  five  or  six  inches  long.  About  a 
drachm  of  distilled  water  should  be  poured  upon  it,  and 
the  tube  drawn  out  and  sealed  before  the  blowpipe,  at 
about  two  inches  from  the  open  end.  The  sealed  tube 
is  then  heated  to  about  300°  to  310°  Fahr.  for  about  an 
hour.*  At  this  temperature  the  fibrin  as  well  as  the 
albumen  of  the  stain  will  dissolve  in  the  water.  When 
the  tube  has  cooled,  it  may  be  opened  with  a  file,  and 
the  liquid  examined.  It  should  have  a  yellow  or  reddish 
color,  and  a  feeble  alkaline  reaction  to  reddened  litmus- 
paper.  Of  course,  it  would  not  be  coagulated  by  heat, 
but  nitric  acid,  chloride  of  mercury,  and  ferrocyanide  of 
potassium  (after  acidifying  with  acetic  acid)  should  yield 
precipitates. 

The  fabric  from  which  the  soluble  matter  has  thus  been 
extracted,  will  generally  retain  some  of  the  iron  of  the 
blood,  and  may  be  examined,  for  further  confirmation, 
by  the  following  tests  : — 

(a)  If  it  be  boiled  in  water  containing  a  little  tannic 

*  This  may  be  effected  either  by  suspending  it  in  oil  which  is  after- 
wards heated  to  that  temperature,  or  by  placing  it  in  a  hot-air  bath. 


BLOOD-CORPUSCLES.  177 

acid,  or  tincture  of  galls,  it  acquires  a  black  or  gray 
color. 

(b)  The  same  piece  may  be  boiled  with  a  little  dilute 
hydrochloric  acid,  the  solution  diluted,  and  tested  with 
ferrocyanide  of  potassium  for  iron. 

(c)  Another  piece  may  be  boiled  with  hydrochloric 
acid,  and  the  solution  tested  for  iron  with  ammonia  and 
hydrosulphate  of  ammonia. 

It  is  always  advisable  to  repeat  the  above  experiments 
with  an  unstained  portion  of  the  same  fabric,  especially 
if  the  latter  be  made  of  a  colored  material. 

Identification  of  blood- si^ots  upon  iron. — Spots  of  blood 
are  generally  much  more  easily  detached  than  those  of 
ordinary  rust,  and  may  be  recognized  by  the  following 
tests : — 

(a)  Digest  in  water  at  about  100°  Fahr.  A  recent 
stain  will  be  dissolved,  and  the  solution  may  be  tested 
by  boiling,  by  nitric  acid,  and  by  chlorine  (see  above). 

(I)  If  water  does  not  dissolve  the  stain,*  boil  it  with 
a  dilute  solution  of  potash,  and  test  the  solution  with 
nitric  acid  and  chlorine. 

(c)  Heat  a  portion  of  the  suspected  rust  in  a  tube,  and 
observe  the  odor. 

(d)  Heat  another  portion  in  a  tube  with  a  fragment  of 
solid  hydrate  of  potash  or  soda;  notice  if  any  ammonia 
is  evolved  during  the  fusion.     All  rust  would  evolve  a 
little  ammonia;  but  an  abundant  evolution  of  this  sub- 
stance would  afford  some  evidence  of  the  presence  of 
blood.     A  part  of  the  nitrogen  contained  in  the  blood 
would  be  converted  into  cyanide  of  potassium,  which 
may  be  detected  by  dissolving  the  fused  mass  in  water, 
adding  a  little  solution  of  protosulphate  and  perchloride 
of  iron,  followed  by  an  excess  of  acetic  acid,  which  should 
leave  a  blue  precipitate  (Prussian  blue). 

464.  White  corpuscles  of  the  blood. — In  addition  to  the. 
red  corpuscles,  there  are  always  present  in  the  blood 

*  Rose  (Journ.  Pharm.,  xxviii.  436)  has  proved  by  direct  experi- 
ment that  hydrated  peroxide  of  iron  (rust)  forms  an  insoluble  com- 
pound with  the  coloring  matter  of  the  blood. 


178  HJEMATIN. 

Fig-  66.  a  few  colorless  particles,* 

somewhat  larger  than  the 
colored  ones,  and  otherwise 
differing  from  them  in  gen- 
eral appearance  and  struc- 
ture (Fig.  66).  They  are 
of  irregular  forms,  some- 
times spherical,  slightly 
granular  on  the  surface. 

magnified      ^  appear  ^  ^  identicalj 

or  nearly  so,  with  the  pecu- 
liar corpuscles  always  present  in  the  lymph  and  the 
chyle.  When  treated  with  .acetic  acid,  the  granular  ex- 
terior becomes  transparent,  as  in  the  corpuscles  of  pus, 
and  one  or  more  internal  nuclei  are  rendered  visible. 

465.  The  proportion  of  corpuscles  present  in  healthy 
blood  is  usually  about  130  parts  in  1000  (573).f 

465a.  Hcematin. — In  order  to  separate  the  peculiar 
coloring  matter  of  the  blood-globules,  freshly  drawn 
blood,  which  has  been  defibrinated  by  stirring,  is  mixed 
with  eight  volumes  of  a  saturated  solution  of  sulphate  of 
soda,  and  set  aside,  in  order  that  the  globules  may  sub- 
side. The  deposit  is  collected  upon  a  filter,  washed  with 
solution  of  sulphate  of  soda,  boiled  with  alcohol  contain- 
ing a  little  sulphuric  acid,  and  filtered  while  hot.  The 
globulin  is  then  removed  from  the  solution  by  precipita- 
tion with  carbonate  of  ammonia,  the  filtered  solution 
evaporated  to  dryness  on  a  water-bath,  and  all  soluble 
matters  removed  from  the  residue  by  boiling  water,  alco- 
hol, and  ether.  By  treating  the  residue  with  ammoniacal 
alcohol,  the  haamatin  is  dissolved,  and  may  be  further 
purified  by  evaporating  the  clear  solution  to  dryness,  and 
washing  the  residue  with  water. 

The  dark  brown  coloring  matter  thus  obtained  is  re- 
.markable  for  its  containing  a  large  proportion  (6*6  per 
cent.)  of  iron,  its  composition  being  represented  (accord- 
ing to  Mulder)  by  the  formula  C44H22N3O6Fe.  If  it  be 

*  These  have  a  lower  specific  gravity  than  the  red  corpuscles,  and, 
therefore,  accumulate  on  the  upper  surface  of  the  clot. 

f  According  to  Denis,  they  contain  one  part  of  solid  matter,  and 
1-8  of  water. 


BLOOD-CRYSTALS.  179 

digested  with  cold  strong  sulphuric  acid,  it  forms  a  brown 
liquid,  and  if  this  be  diluted,  hydrogen  is  evolved,  and 
a  dark  brown  substance  left,  whilst  sulphate  of  iron 
(FeO,S03)  is  found  in  solution.  Chlorine  also  removes 
the  iron,  but  at  the  same  time  destroys  the  color,  pro- 
ducing a  white  coagulum.  In  its  general  chemical 
characters,  ha3matin  resembles  the  albuminous  class  of 
substances. 

Hcematoidin,  or  blood-crystals. — When  a  drop  of  blood 
is  diluted  with  a  little  water  on  a  slip  of  glass,  lightly 
covered  with  a  piece  of  thin  glass,  and  left  in  the  sunlight 
for  some  hours,  minute  red  prismatic  crystals  of  htema- 
toidin  will  sometimes  be  perceived. 

Ha3matoidin  is  also  met  with  in  old  extravasations,  and 
Kobin*-has  examined  a  mass  of  crystals  of  this  substance, 
weighing  about  fifty  grains,  obtained  from  a  hydatid  cyst 
in  the  liver.  An  analysis  of  these  crystals  led  to  the  for- 
mula C14H8NO2  +  IIO,  and  Eobin  believes  them  to  repre- 
sent hgematin  which  has  lost  all  its  iron,  and  acquired  an 
atom  of  water.  The  substance  obtained  by  treating 
hasmatin  with  sulphuric  acid  has  almost  exactly  the  same 
composition.  Haematoidin  is  very  sparingly  soluble  in 
water,  and  insoluble  in  alcohol;  but  it  dissolves  in  am- 
monia, yielding  a  red  solution. 

Lehmann  obtained  a  red  crystalline  substance  from 
the  blood  of  guinea-pigs,  rats,  or  mice,  by  washing  the 
clot  with  water,  filtering  the  red  liquid,  and  passing  first 
a  current  of  oxygen,  and  afterwards  carbonic  acid.  After 
a  time  the  crystals  separate,  and  may  be  washed  with  a 
little  water.  This  substance,  which  has  been  named 
haBmato-crystallin,  dissolves  sparingly  in  water,  the  solu- 
tion being  coagulated  by  heat,  but  not  by  chloride  of 
mercury.  In  composition  it  somewhat  resembles  albu- 
men, containing  more  nitrogen  and  less  sulphur.  Much 
obscurity  still  remains  to  be  cleared  up  with  respect  to 
these  crystalline  bodies  obtained  from  blood. 

Dr.  Carter  ("Ed.  Med.  Journal,"  August,  1859)  ob- 
tained from  serum  a  substance  yielding  indigo  by  decom- 
position, similar  to  that  extracted  from  urine  (page  40). 

*  Compt.  Rend.,  xli.  506. 


180  HEALTHY    BLOOD. 

SECTION  III. 
Albumen. 

466.  This  is  one  of  the  most  important  of  the  consti- 
tuents of  the  blood,  and,  with  the  exception  of  the  red 
corpuscles,  is  present  in  larger  quantity  than  any  of  the 
other  solid  matters  contained  in  it.     It  is  held  in  solu- 
tion in  the  serum,  where  it  may  readily  be  shown  to 
exist  by  gently  boiling  in  a  tube  a  little  of  the  clear, 
colorless  fluid  from  which  the  coagulated  clot  of  fibrin 
and  corpuscles  has  subsided.    As  soon  as  the  temperature 
reaches  about  170°,  the  albumen  begins  to  coagulate,  and 
on  being  boiled  for  a  short  time,  separates  entirely  in  the 
insoluble  form. 

467.  It  may  also  be  precipitated  from  its  solution  in 
the  serum,  by  adding  to  the  clear  fluid  a  few  drops  of 
dilute  nitric   or  hydrochloric  acid  (136,  141).     Acetic 
acid  fails  to  precipitate  it;  but  if  ferrocyanide  of  potas- 
sium be  added  to  the  acidified  solution,  a  dense  white 
precipitate  is  produced,  even  when  the  albuminous  liquid 
is  very  dilute. 

468.  When  gently  warmed  with  strong  hydrochloric 
acid,  albumen  dissolves,  forming  a  purple-colored  solu- 
tion, in  which  respect  it  resembles  fibrin  and  casein. 

469.  When  moistened  with  strong  nitric  acid,  albumen 
becomes  yellow,  owing  to  the  formation  of  xanthoproteic 
acid  (2HO,C34H24N4O12),  which,  together  with  oxalic  acid 
(HO,C203),  ammonia  (NH^  nitric  oxide  (NO2),  and  nitro- 
gen, is  always  formed  by  the  action  of  strong  nitric  acid 
on  the  so-called  compounds  of  protein. 

469a.  Heated  with  a  solution  of  nitrate  of  mercury 
(HgO,N05),  albumen  becomes  intensely  red  (14la.) 

470.  It  appears  from  the  results  of  numerous  analyses 
that   the   average  amount   of  dry  albumen  present   in 
healthy  blood  is  rather  more  than  70  parts  in  1000  (573). 

471.  The  composition  of  albumen  is  usually  expressed 
by  Mulder's  formula  (C400H310lSr500]20S2P);  but  considera- 
ble uncertainty  still  hangs  over  the  real  nature  of  this 


FIBRIN.  181 

class  of  bodies.*  It  is  even  doubtful  whether  any  phos- 
phorus exists  in  albumen,  except  in  the  state  of  phos- 
phoric acid,  as  a  constituent  of  the  ash.  By  some  chemists 
albumen  is  regarded  as  containing  C144EI110N18SaO42  ;  and 
since  the  serum  of  blood  always  contains  nearly  2  per 
cent,  of  soda,  they  consider  it  to  consist  of  an  albuminate 
of  soda,  in  which  one  atom  of  the  above  albumen  is  com- 
bined with  each  atom  of  soda.  As  the  more  important 
peculiarities  of  albumen  have  been  already  noticed  in 
the  chapter  on  morbid  urine  (133,  235,  &c.),  they  need 
not  be  again  described. 

SECTION  IV. 
Fibrin. 

472.  This  substance,  of  which  muscular  fibre  is  chiefly 
composed,  is  closely  allied  in  chemical  composition  and 
general  properties  to  albumen;  and  it.  is,  indeed,  not  im- 
probable that  both  are,  in  their  chemical  relations,  merely 
modifications  of  the  same  compound,  which,  from  the 
circumstance  of  its  being  apparently  the  basis,  not  only 
of  albumen  and  fibrin,  but  also  of  casein  (625)  and  some 
other  analogous  substances,  has  been  called  protein,  from 
v«,  /  am  first.^ 


*  The  percentage  composition  of  the  three  so-called  protein  com- 
pounds, albumen,  fibrin,  and  casein,  is  as  follows  :  — 

Albumen.  Fibrin.  Casein. 

Carbon  .  55-46  54-45  54-66 


Hydrogen 
Nitrogen 
Oxygen . 
Sulphur 


7-15 

15-72 

21-55 

•92 


Phosphorus 

100-00  100-00  100-00 

The  mineral  constituents,  such  as  phosphate  of  lime,  from  which 
these  substances  can  never  be  completely  separated,  have  been  ex- 
cluded from  this  calculation. 

A  peculiar  modification  of  albumen  (albuminose  or  peptone)  has  been 
observed  in  the  liver  and  in  blood,  differing  from  normal  albumen 
in  not  coagulating  when  heated,  and  from  casein  in  not  being  preci- 
pitated by  acids. 

t  The  existence  of  protein  as  an  independent  proximate  principle 
appears  very  doubtful.  Mulder  represented  fibrin  as  a  compound  of 

16 


182  HEALTHY    BLOOD. 

473.  While  circulating  in  the  vessels,  the  fibrin  of  the 
blood  is  held  in  a  state  of  solution  in  the  liquor  sanguinis ; 
but  no  sooner  is  the  blood  removed  from  the  system, 
than  it  begins  to  separate  in  a  solid  state,  after  which  it 
becomes  quite  insoluble  in  water.     This  solidification  of 
the  fibrin  is  the  cause  of  the  well-known  phenomenon  of 
coagulation,  which  blood  experiences  almost  immediately 
after  it  is  drawn;  and  although  the  coagulum  or  clot  con- 
tains the  blood-corpuscles  in  addition  to  the  fibrin,  these 
have  merely  been  entangled  in  the  network  of  coagulating 
fibrin,  and  do  not  themselves  play  any  active  part  in  the 
process  of  coagulation.* 

474.  The  coagulation  of  blood  may  be  retarded,  and 
even  altogether  prevented,  by  the  presence  of  certain  salts 
and  other  substances.     The  alkalies,  for  example,  and 
their  carbonates  and  acetates,  entirely  prevent  it;   and 
tolerably  strong  solutions  of  sulphate  of  soda,  nitrate  of 
potash,  nitrate  of  lime,  chloride  of  ammonium,  and  some 
other  salts,  retard  it  for  a  considerable  time.     The  latter 
salt,  indeed,  gradually  dissolves  fibrin,  after  it  has  been 
allowed  to   coagulate.     Most  of  the  dilute  acids,  also, 
cause  blood  to   retain  its  fluidity,  though  it  becomes, 
under  their  influence,  more  viscous   and  syrupy  in  its 
consistence. 

475.  Contact  with  certain  animal  membranes  also  ap- 
pears to  exercise  a  retarding  influence  on  the  coagulation 
of  the  blood.     When  infused  into  the  cellular  tissue,  it 
has  been  known  to  continue  uncoagulated  for  some  weeks; 
and  even  in  a  tied  artery,  it  remains  some  hours  without 
coagulating. 

476.  It  appears  from  the  experiments  of  M.  Denis,  that 
if  moist  fibrin  be  digested  in  a  solution  of  nitrate  of 
potash  containing  a  little  soda,  at  a  temperature  of  about 
100°  Fahr.,  it  becomes  gradually  converted  into  a  sub- 
ten  atoms  of  protein  (C40H31N5012)  with  one  atom  of  sulphur  and  one 
of  phosphorus,  but  the  presence  of  the  latter,  except  in  the  ash  of 
fibrin,  is  disputed.     The  fibrin  of  muscle  does  not  appear  to  be  identi- 
cal with  that  of  blood,  the  latter  containing  a  smaller  proportion  of 
sulphur. 

*  According  to  Dr.  Richardson,  the  coagulation  of  the  fibrin  is  due 
to  the  escape  of  ammonia,  by  which  it  was  previously  held  in  solution. 


HEALTHY    BLOOD.  183 

stance  in  almost  every  respect  identical  with  albumen  ;* 
being  soluble  in  water,  and  coagulable  by  heat.  This 
change  is  said  to  be  most  readily  produced  when  the 
fibrin  employed  in  the  experiment  has  been  obtained 
from  venous  blood,  by  allowing  it  to  coagulate  spon- 
taneously; while,  if  it  is  separated  by  agitation,  or  if  the 
blood  be  arterial,  it  scarcely  experiences  any  alteration 
in  the  saline  solution.  By  drawing  blood  into  a  solution 
of  sulphate  of  soda,  so  as  to  prevent  the  coagulation  of 
the  fibrin,  filtering  off  the  globules,  and  saturating  the 
filtrate  with  chloride  of  sodium,  Denis  obtained  a  preci- 
pitate of  fibrin,  which  dissolved  in  water,  forming  a 
solution  which  gave,  after  a  short  time,  a  transparent 
coagulum  of  fibrin. 

477.  Pure  fibrin  may  be  obtained  without  difficulty,  by 
receiving  the  blood,  as  it  flows  from  the  body;  in  a  clean 
porcelain  dish,  and  stirring  it  well  for  some  little  time 
with  a  glass  rod ;  or  the  blood  may  be  shaken  with  a  few 
small  fragments  of  lead,  in  a  closed  glass  flask.     The 
fibrin,  as  it  coagulates,  collects  in  loose  fibrous  masses 
round  the  rod  or  fragments  of  lead,  colored  slightly  red, 
owing  to  the  imprisonment  of  a  few  corpuscles  within 
the  network  of  fibrin.     These  may  be  removed  by  tying 
the  coagulum  in  a  piece  of  fine  muslin,  and  washing  it 
under  a  stream  of  cold  water  until  the   mass  becomes 
colorless.     In  this  state;  it  still  contains  traces  of  fatty 
matter  and  inorganic  salts,  together  with  a  considerable 
amount  of  water.     To  obtain  the  fibrin,  therefore,  in  a 
state  of  perfect  purity,  the  washed  coagulum   must  be 
dried  on  a  chloride  of  calcium  bath  at  a  temperature  of 
about  250°,  and  the  dry  mass  then  reduced  to  fine  powder 
in  a  mortar.     The  pounded   fibrin   may  afterwards  be 
washed  successively  with  alcohol,  ether,  and  dilute  hydro- 
chloric acid;  and  lastly,  macerated  with  cold  or  lukewarm 
water,  until  all  the  soluble  matter  is   removed ;   after 
which  it  may  be  dried  as  before  at  a  temperature  of  about 
250°. 

478.  If  the  blood  from  which  we  wish  to  extract  the 


*  Fibrin  suffers  a  similar  change  when  heated  with  water  to  about 
3000  Fahr.,  in  a  sealed  tube. 


184  HEALTHY    BLOOD. 

fibrin  has  already  coagulated,  the  clot  is  first  gently 
pressed  between  folds  of  bibulous  paper,  in  order  to 
squeeze  out  the  greater  part  of  the  adhering  serum,  and 
then  cut  into  thin  shreds  with  a  sharp  knife.  The  finely- 
divided  clot  is  then  washed  in  a  muslin  bag  under  a 
gentle  stream  of  cold  water,  until  it  becomes  colorless, 
by  which  means  the  imprisoned  corpuscles  are  washed 
out  of  the  fibrous  mass.  The  latter  is  then  dried,  and 
reduced  to  powder,  and  subsequently  purified  by  washing 
and  drying  in  the  manner  above  described  (477). 

479.  Fibrin  thus  prepared  is  a  pale,  yellowish,  horny- 
looking  substance,  hard,  brittle,  and,  if  all  traces  of  fat 
have  been  removed,  transparent.    It  is  perfectly  tasteless, 
and  insoluble  in  water,  alcohol,  and  ether;  if  kept  for  a 
short  time  in  water,  however,  it  gradually  softens,  swells 
up,  and  reassumes  the  appearance  it  had  previous  to 
desiccation.     When  digested  with  acetic  and  most  of  the 
other  acids,  fibrin  becomes  gelatinous,  and  is  in  that  state 
soluble  in  water.     The  acid  solution,  when  treated  with 
ferrocyanide  of  potassium,  gives  a  copious  white  preci- 
pitate, similar  to  that  caused  in  albuminous  solutions. 
Fibrin  is  also  dissolved  by  digestion  in  a  dilute  solution 
of  nitre,  the  liquid  coagulating  when  heated.     Like  albu- 
men, and  the  other  modifications  of  protein,  it  forms, 
when  gently  warmed  with  strong  hydrochloric  acid,  a 
purple-colored  solution.     With  nitric  acid,  also,  fibrin 
behaves  like  the  other  protein  compounds,  forming  the 
yellow  xanthoproteic  acid  (469).     It  also  becomes  red 
when  heated  with  solution  of  nitrate  of  mercury  (141a). 

479a.  The  fibrin  of  muscle  (sometimes  called  syntonin) 
differs  somewhat  in  properties  from  that  of  blood.  It 
does  not  dissolve  in  a  dilute  solution  of  nitre,  but  may  be 
dissolved  by  digestion  in  very  dilute  hydrochloric  acid 
(1  of  acid  to  1000  of  water),  whilst  blood-fibrin  swells  up 
and  becomes  transparent,  but  does  not  dissolve. 

480.  When  examined  under  the  microscope,  coagulated 
fibrin  appears  to  consist  of  a  rude  network  of  amorphous 
threads,  together  with  detached  aggregations  of  irregular 
form,  similar  to  albumen. 

481.  The  average  proportion  of  dry  fibrin  present  in 
healthy  blood  appears  to  be  rather  more  than  two  parts 
in  a  thousand  (573). 


HEALTHY    BLOOD.  185 

SECTION  V. 
Extractive  Matters. 

482.  Of  the  real  chemical    nature  of  the  substances 
included  under  the  name  of  extractive  matters,  little  is 
yet  definitely  known,  though  they  have  frequently  en- 
gaged the  attention  of  chemists.   It  is  probable,  however, 
that  further  researches  will,  ere  long,  throw  new  light 
upon  this  at  present  obscure  class  of  substances.     They 
include  all  the  undefined,  uncrystallizable  organic  matters 
which  are   soluble  in    water;    or,    in  other    words,  the 
extractive  matters  of  the  blood  may  be  said  to  include  all 
the  organic  substances  contained  in  it,  with  the  exception 
of  the  corpuscles,  albumen,  fibrin,  and  fatty  matters. 

483.  Extractive  matters  are  usually  divided  iuioakohol 
extractive  and  water  extractive;   the  first  including  that 
portion  which  is  soluble  both  in  water  and  alcohol ;    and 
the  latter,  that  which  is  soluble  in  water  and  insoluble  in 
alcohol.   They  are  of  a  brown  or  yellowish  color,  and  are 
characterized  by  their  solutions  giving  brown  precipitates 
with  acetate  of  lead,  but  none  with  bichloride  of  mercury. 
A  solution  of  the  alcohol  extractive  is  precipitated  by  an 
infusion  of  galls,  which  reagent  causes  little  or  no  change 
in  the  water  extractive. 

484.  Traces  of  urea  are  probably  always  present  in  the 
blood,  and  would  be  contained  in  the  alcohol  extractive. 
The  method  of  detecting  it  will  be  described  further  on 
(598).     The  minute  traces  of  uric  acid  which  appear  to 
be  usually  present  even  in  healthy  blood,  would  be  con- 
tained in  the  water  extractive  ;  the  mode  of  detecting  them 
is  described  in  paragraph  604.* 

485.  The   amount  of  extractive  matters   present  in 
healthy  blood  seems  to  vary  from  one  to  three  parts  in  a 
thousand. 


*  Sugar  has  been  discovered  in  minute  proportion  in  normal  blood. 
Campbell  has  also  indicated  the  presence  of  a  little  formic  acid  in  the 
serum. 

16* 


186  HEALTHY    BLOOD. 

SECTION  VI. 
Fatty   Matters. 

486.  Our  knowledge  of  the  fatty  matters  contained  in 
the  blood  is  at  present  far  from  being  complete.     They 
are  usually  divided  into  oily  fats  and  crystalline  fats  ;  the 
first  being  soluble  in  cold  alcohol,  and  the  latter  insoluble. 
The  oily  fats  appear  to  consist  chiefly  of  oleic  (H 0,  C36 
ff3303)  and  margaric  (HO^G^H^O^  acids;  the  crystalline 
fatty  matter  is  probably  a  mixture  of  serolin  with  traces 
of  cholesterin  (C52H44O2),  together  with  one  or  more  solid 
fats  containing  phosphorus.* 

487.  To  obtain  these  fatty  matters,  a  quantity  of  blood 
is  evaporated  to  dry  ness  on  a  water-bath,  and  the  dry 
residue,  after  being  reduced  to  powder,  is  digested  in  hot 
ether,  successive  portions  of  which  must  be  added  as  long 
as  anything  appears  to  be  dissolved  by  it.     The  ethereal 
solution  is  then  evaporated  to  dryness  on  a  water-bath, 
and  the  residue,  consisting  of  the  mixed  fats,  treated  with 
cold  alcohol,  which  will  dissolve  out  the  oily  fats,  and 
leave  the  crystalline  matters  undissolved.     The  first  may 
be  obtained  by  evaporating  the  alcoholic  solution  on  a 
water-bath ;   and  the  undissolved  crystalline  fats  may  be 
dissolved  in  boiling  alcohol,  from  which  they  will  almost 
entirely  separate,  as  the  liquid  cools,  in  the  form  of  small 
crystalline  scales. 

488.  The  quantity  of  fatty  matters  present  in  healthy 
blood  appears  to  vary  from  1-5  to  2'5  in  1000  parts  (573). 

SECTION  VII. 
Fixed  Saline  Matters. 

489.  The  ash  left  after  the   incineration   of  the   dry 
residue  of  evaporated  blood  appears  to  contain  the  follow- 
ing substances : — viz.,  the  chlorides  of  sodium  and  potas- 
sium ;   the  phosphates  of  lime,  magnesia,  and  soda ;   the 

*  The  serum  also  contains  minute  proportions  of  one  or  more  of  the 
volatile  fatty  acids  (e.  g.  butyric  or  caproic),  as  shown  by  the  odor 
which  is  developed  on  mixing  the  blood  with  sulphuric  acid,  and 
varies  in  different  animals. 


UEALTHY    BLOOD.  187 

sulphates  of  potash  and  soda;  and  oxide  of  iron  derived 
from  the  hsematin  (455).  If  the  ash  has  been  obtained 
by  the  incineration  of  the  serum,  traces  of  alkaline  and 
earthy  carbonates  will  probably  be  rendered  apparent  by 
the  effervescence  caused  by  the  addition  of  an  acid  ;  but 
if  the  ash  has  been  obtained  by  the  incineration  of  the 
entire  blood,  no  trace  of  carbonates  will  be  observable  on 
the  addition  of  the  acid.  The  cause  of  this  appears  to 
be,  that  some  of  the  fatty  matters  present  in  the  clot 
contain  traces  of  phosphorus  (486),  which,  during  com- 
bustion, is  converted  into  phosphoric  acid  (P05);  and  the 
phosphoric  acid  thus  formed  decomposes  the  small  quan- 
tity of  carbonates  derived  from  the  serum,  converting 
them  into  phosphates. 

490.  The  saline  matters  of  the  blood  may  be  conveni- 
ently divided  into  the  alkaline  salts,  which  readily  dissolve 
in  water,  and  the  earthy  salts,  which  require  an  acid  for 
their  solution.     The  alkaline  portion  of  the  ash  consists 
of  the  chlorides  of  sodium  and  potassium  ;  the  sulphates 
of  potash  and  soda ;  and  phosphate,  with  possibly  traces 
of  carbonate  (489)  of  soda.      The  earthy  or  insoluble 
portion  contains  the  phosphates  of  lime  and  magnesia  ; 
oxide  of  iron  derived  from  the  red  coloring  matter ;  and 
possibly  a  little  earthy  carbonate  (489).     The  presence 
of  the  bases  and  acids  contained  in  these  several  salts 
may  be  shown  by  the  following  experiments. 

491.  Digest  from  twenty  to  thirty  grains  of  the  ash  in 
warm  water,  in  order  to  dissolve  out  the  alkaline  salts, 
and  filter  the  solution  from  the  insoluble  portion.     The 
aqueous  solution  thus  obtained  may  be  first  tested,  retain- 
ing the  earthy  residue  for  subsequent  examination  (499). 

492.  If  the  aqueous  solution  is  at  all  dilute,  it  should 
first  be  concentrated  by  evaporation.     To  a  little  of  the 
concentrated  solution,  add  a  slight  excess  of  tartaric  acid 
(2HO,C8H4010)}  and  agitate  the  mixture  with  a  glass  rod. 
A  colorless  crystalline  precipitate  of  the  bitartrate  show's 
the  presence  of  POTASH. 

493.  To  another  portion  of  the  solution  add  a  solution 
of  bichloride  of  platinum  (PtCl2\  and  allow  the  mixture 
to  evaporate  to  dryness,  either  spontaneously  or  at  a  very 
gentle  heat.    Minute,  yellow,  granular  crystals   of  the 


188  HEALTHY    BLOOD. 

double  chloride  of  platinum  and  potassium  (KCl,PtC!2) 
will  be  found  deposited,  also  showing  the  presence  of 
POTASH.  In  addition  to  these  will  be  seen  long,  yellow, 
needle-shaped  crystals  of  the  double  chloride  of  platinum 
and  sodium,  proving  the  presence  of  SODA.  If  the  bichlo- 
ride of  platinum  has  not  been  added  in  sufficient  quantity 
to  combine  with  the  whole  of  the  soda,  a  few  detached 
cubical  crystals  of  chloride  of  sodium  will  also  be 
deposited,  which  may  be  proved  to  be  such  by  their 
well-known  taste. 

494.  The   presence  of  soda  may  also   be   shown   by 
adding  to  a  little  of  the  strong  aqueous  solution  a  few 
drops  of  antimoniate  of  potash   (KO,Sl)0^,  which  will 
gradually  cause  a  colorless  crystalline  precipitate  of  anti- 
moniate of  soda  (NaO,Sb05). 

495.  To  another  portion  of  the  aqueous  solution  of  the 
ash,  add  a  solution  of  chloride  of  barium,  or  nitrate  of 
baryta,  as  long  as  it  causes  any  precipitate.    The  sulphu- 
ric, phosphoric,  and  (if  any  (489)  ),  carbonic  acids  are 
thus  thrown  down  in  combination  with  baryta.     The 
mixture  containing  the  precipitate  thus  produced  is  now 
strongly  acidified  with  hydrochloric  acid,  and  warmed.  If 
effervescence  occurs  on  the  acid  of  the  acid,  CARBONIC 
ACID  is  probably  present.     The  presence  of  SULPHURIC 
ACID  is  shown  by  a  portion  of  the  precipitate  (sulphate 
of  baryta)  proving  insoluble  in  the  acid. 

496.  Filter  the  acid  mixture  formed  in   (495),   and 
neutralize  the  filtered  liquid  with  ammonia.     The  phos- 
phate of  baryta  (2BaO,HO,P05),  which  had  been  dissolved 
by  the  acid,  is  reprecipitated,  indicating  the  presence  of 

PHOSPHORIC  ACID  (498). 

497.  Acidify  another  portion  of  the  aqueous  solution 
of  the  ash  with  nitric  acid  ;  add  a  slight  excess  of  nitrate 
of  silver,  and  filter  the  liquid  from  the  white  precipitate 
occasioned  by  the  silver  salt.     This  precipitate  may  be 
proved  to  consist  of  chloride  of  silver  (HYDROCHLORIC 
ACID),  by  beiug  readily  soluble  in  ammonia,  and  insoluble 
in  nitric  acid. 

498.  Accurately  neutralize  the  acid  solution  formed  in 
(497),  with  dilute  ammonia;   the  pale  yellow  phosphate 
of  silver  (3AgO,PO5),  which  had  been  held  in  solution  by 


HEALTHY    BLOOD.  189 

the  excess  of  acid,  will  now  be  precipitated,  showing  the 
presence  of  PHOSPHORIC  ACID  (496).* 

499.  The   earthy  portion  of  the   ash,  which   proved 
insoluble  in  water  (491),  may  now  be  examined.    It  is  to 
be  dissolved  in  as  small  a  quantity  as  possible  of  dilute 
hydrochloric  acid,  a  gentle  heat  being  applied  if  necessary. 
If  effervescence  occurs  on  the  addition  of  the  acid,  CAR- 
BONIC ACID  is  present  (489). 

500.  A  little  of  the  acid  solution  may  now  be  nearly 
neutralized  with  dilute  ammonia,  which  should  not  be 
added  in  sufficient  quantity  to  cause  any  precipitate.    The 
liquid  is  then  tested  with  a  drop  or  two  of  a  solution  of 
ferrocyanide  of  potassium,  which  will  cause,  either  at  once 
or  in  the  course  of  a  few  minutes,  a  blue  color,  owing  to 
the  formation  of  the  ferrocyanide  of  iron  (Fe4Fcy3),  show- 
ing the  presence  of  IRON. 

501.  The  rest  of  the  acid  solution  of  the  earthy  portion 
of  the  ash  may  now  be  supersaturated  with  ammonia, 
which  will  throw  down  a  white  gelatinous  precipitate  of 
earthy  phosphates.     A  little  of  this  precipitate  may  be 
examined  under  the  microscope,  when  it  will  be  found 
to  consist  chiefly  of  amorphous  particles  of  phosphate  of 
lime  (3CaO,PO3),  with  a  few  crystals  of  the  double  phos- 
phate of  ammonia  and   magnesia   (2MgO,NH4O;PO54- 
12Aq).     The  precipitate  thrown  down  by  the  ammonia 
may  also  be  examined  for  LIME,  MAGNESIA,  and  PHOSPHO- 
RIC ACID  by  redissolving  it  in  acetic  acid,  and  testing  the 
solution  in  the  manner  described  in  paragraph  47. 

502.  The  quantity  of  alkaline  salts  usually  present  in 
healthy  blood,  varies  from  about  six  to  ten  parts  in  1000 ; 
and  that  of  earthy  salts  from  0'5  to  1*5  in  1000  parts. 

*  The  phosphoric  acid  may  be  detected  with  greater  certainty  by 
perchloride  of  iron,  or  the  mixture  of  sulphate  of  magnesia,  chloride 
of  aminouium  and  ammonia  (41). 


190         QUANTITATIVE    ANALYSIS    OF    BLOOD. 


CHAPTER  II. 

QUANTITATIVE  ANALYSIS  OF  THE  BLOOD. 

503.  A  COMPLETE  quantitative  analysis  of  the  blood, 
including  the  separation  from  each  other  and  estimation 
of  all  the  ingredients,  would  be,  even  if  our  knowledge 
and  resources  were  much  less  limited  than  they  are,  in 
the  highest  degree  complicated  and  difficult,  while  at 
present  it  may  be  said  to  be  altogether  impracticable. 
For  most  purposes,  however,  a  comparatively  incomplete 
analysis,  embracing  the  determination  of  the  more  im- 
portant ingredients,  is  all  that  is  required;  and  in  the 
majority  of  cases  a  knowledge  merely  of  the  proportion 
of  fibrin,  the  corpuscles,  and  the  solids  contained  in  the 
serum,  is  what  the  medical  practitioner  chiefly  requires. 

504.  I  will  first  describe  the  mode  of  conducting  such  an 
analysis,  by  which  the  amount  of  water, corpuscles,  fibrin, 
and  solids  contained  in  the  serum  may,  with  very  little 
difficulty,  be  ascertained ;  and  subsequently  go  through 
a  somewhat  more  complete  scheme,  by  which,  in  addition 
to  the  above  substances,  the  more  important  constituents 
of  the  serum  may  also  be  individually  estimated.     (See 
sections  3  and  4.) 

505.  When  the  blood  intended  for  analysis  can  be  col- 
lected in  the  proper  vessels  as  it  flows  from  the  body,  the 
process  is  somewhat  simpler  than  when  it  has  been  al- 
lowed to  coagulate ;  and  the  results  are  generally  more 
accurate.     As,  however,  this  is  frequently  impracticable, 
I  will  also  describe  the  method  by  which  the  analysis  by 
coagulated  blood  may  be  effected. 


QUANTITATIVE    ANALYSIS    OF    BLOOD.        191 

SECTION  I. 

Quantitative  Analysis  of  Uncoagulated  Blood,  including  the 
estimation  of  the  water,  corpuscles,  fibrin,  and  the  solid 
matters  contained  in  the  serum. 

506.  Before  proceeding  to  collect  the  blood  as  it  flows 
from  the  body,  for  the  purpose  of  analysis,  the  experi- 
menter should  provide  himself  with  three  vessels,  the 
exact  weight  of  each  of  which  is  to  be  carefully  ascer- 
tained and  noted.     These  vessels  are : — 

1.  A  six  or  eight-ounce  bottle,  provided  with  a  stopper; 
this  bottle  should  be  perfectly  clean  and  dry,  and  of 
known  weight.     Eight  or  ten  small  strips  of  thin 
sheet  lead,  about  half  an  inch  square,  the  weight  of 
which  should  also  be  known,  are  put  into  the  bottle, 
which  will  then  be  ready  to  receive  the  blood  (507). 
This  bottle  is  used  for  effecting  the  separation  of  the 
fibrin. 

2.  A  small  platinum  or  Berlin  porcelain  capsule,  capa- 
ble of  holding  from  half  an  ounce  to  an  ounce  of 
water.     This  is  used  for  estimating  the^  proportion 
of  water  in  the  blood  (508). 

3.  A  rather  tall,  upright  beaker,  or  cylindrical  glass, 
capable  of  holding  about  six  ounces  of  water. 

507.  The*blood  may  now  be  collected.     About  five  or 
six  ounces  of  the  fluid  are  first  poured  into  the  bottle 
containing  the  fragments  of  lead,  which  should  then  be 
tightly  closed  with  the  stopper,  and  kept  gently  agitated 
for  about  a  quarter  of  an  hour,  in  order  to  allow  the 
whole  of  the  fibrin  to  coagulate,  and  attach  itself  to  the 
pieces  of  lead  (477).     This  portion  of  blood  we  will  call 
A  (510). 

508.  Two  or  three  drachms  of  blood  are  collected  in 
the  capsule,  which  is  then  again  accurately  weighed,  and 
the  weight  of  the  empty  capsule,  previously  ascertained 
(506),  deducted  from  the  gross  weight,  in  order  to  deter- 
mine the  exact  quantity  of  blood  contained  in  it.    It  may 
then  be  placed  on  a  water-bath,  and  evaporated  to  dry- 
ness.     This  portion  we  will  call  B  (514). 

509.  The  beaker,  or  cylindrical  glass,  is  to  be  nearly 
filled  with  the  freshly-drawn  blood,  covered  with  a  glass 


192        QUANTITATIVE    ANALYSIS    OF    BLOOD. 

plate,  and  set  aside  in  a  tolerably  cool  place  for  twenty- 
four  hours;  at  the  end  of  which  time  it  will  be  found  to 
be  thoroughly  coagulated,  and  separated  into  a  firm  clot 
and  clear  serum.  This  portion  we  will  call  C  (516). 

510.  Treatment  of  the  portion  A. — When  the  blood  has 
been  gently  shaken  for  abou^t  a  quarter  of  an  hour,  imme- 
diately on  being  placed  in  the  bottle  (507),  the  fibrin  will 
be  found  to  have  separated,  and  collected  round  the  frag- 
ments of  lead  which  have  been  previously  introduced. 
The  outside  of  the  bottle  is  then  cleaned  with  a  wet  cloth, 
and  wiped  dry. 

511.  The  weight  of  the  bottle,  with  its  contents,  is  now 
taken,  in  order  to  ascertain  the  exact  quantity  of  blood 
employed  in  the  experiment,  which  is  known  by  deduct- 
ing from  the  gross  weight  that  of  the  empty  bottle  and 
the  lead,  the  difference  being  the  weight  of  blood  con- 
tained in  it. 

512.  The  stopper  is  now  removed,  and  the  contents  of 
the  bottle  poured  out  upon  a  piece  of  fine  muslin  placed 
in  a  small  basin  or  saucer.     The  liquid  portion  is  care- 
fully drained  off,  and  may  be  thrown  away;  after  which 
the  fibrin  adhering  to  the  lead  is  to  be  washed  with  a 
gentle  stream  of  cold  water,  until  it  becomes  colorless, 
in  order  to  separate  from  it  the  whole  of  the  corpuscles 
and  serum.     During  the  washing,  the  spongy  aggrega- 
tions of  fibrin  may  be  gently  pressed  occasionally  between 
the  fingers,  care  being  taken  that  none  of  the  fragments 
are  lost.     When  clean,  the  fibrin  is  to  be  placed  in  a 
small  evaporating  dish,  and  dried  on  a  chloride  of  cal- 
cium bath,  at  a  temperature  of  220°  or  230°,  until  it 
ceases  to  lose  weight.     It  is  unimportant  whether  it  is 
dried  and  weighed  with  the  pieces  of  lead,  or  first  sepa- 
rated from   them,  since  the  weight  of  the  lead,   being 
known  (506),  may  be  deducted  from  the  gross  weight  of 
the  lead  and  fibrin,  the  difference  being  that  of  the  fibrin. 

513.  The  weight  thus  obtained  represents   the  pro- 
portion of  FIBRIN  in  the  quantity  of  blood  used  in  the 
experiment ;  the  proportion  in  1000  parts  of  blood  may 
afterwards  be  ascertained  by  the  following  calculation: — 

/  Wt.  of  blood  )       /  Wt.  of  fibrin  )       ,  nnn     (  Quantity  of  fibrin  in  ) 
(  employed.    J   :    (     obtained.     )  '' '  :\  1000  parts  of  blood.  ) 


QUANTITATIVE    ANALYSIS    OF    BLOOD.        193 

514.  Treatment  of  the  portion  13. — The  capsule  contain- 
ing the  portion  B,  after  being  accurately  weighed  (508), 
is  allowed  to  remain  on  the  water-bath  (or  still  better,  on 
a  chloride  of  calcium  bath,  heated  to  about  220°  or  230°), 
until  it  ceases  to  lose  weight  on  being  weighed  at  inter- 
vals of  half  an  hour  or  an  hour,  care  being  taken  to  wipe 
the  outside  clean  and  dry  each  time.     When  the  weight 
becomes  constant,  it  may  be  concluded  that  the  whole  of 
the  water  has  been  expelled. 

515.  From  the  weight  thus  obtained  that  of  the  empty 
capsule  is  now  to  be  deducted;  the  difference  being  the 
weight -of  the  ENTIRE  SOLID  MATTER  contained  in  the 
quantity  of  blood  operated  on.     The  difference  between 
the  weight  of  this  dry  residue  and  that  of  the  blood  be- 
fore evaporation,  or,  in  other  words,  the  loss  which  it  has 
experienced  during  the  evaporation,  will  then  represent 
the  amount  of  WATER  contained  in  the  quantity  of  blood 
employed  in  the  experiment.     The  proportion  of  solid 
matter  present  in  1000  parts  of  the  blood,  may  therefore 
be  calculated  in  the  following  manner: — 

(Wt.  of      )       (  Wt.  of  )  f  Proportion  of  solid ) 

blood       \r\      dry      \ : :  1000  :  \      matter  in  1000      Y 
evaporated.  )       (  residue.  J  (  parts  of  the  blood.  J 

516.  Treatment  of  the  portion  0. — The  third  portion  of 
blood  which  was  collected  in  the  beaker  (509),  is  allowed 
to  stand  for  about  twenty-four  hours,  or  until  it  separates 
into  a  firm  clot  and  clear  serum.     Two  or  three  drachms 
of  the  clear  serum  are  carefully  poured  off  from  the  clot 
into  a  small  platinum  or  porcelain  capsule,  similar  to  that 
before  used  (506),  the  weight  of  which  has  been  previously 
accurately  noted.     The  capsule  with  the  serum  is  now 
weighed,  to  ascertain  the  quantity  of  the  latter  employed 
in  the  experiment,  and  then  evaporated  to  perfect  dry- 
ness  on  a  chloride  of  calcium  bath  at  a  temperature  of 
about  230°,  until  it  ceases  to  lose  weight.     The  loss  of 
weight  which  it  experiences  during  evaporation,  repre- 
sents the  amount  of  water  in  the  quantity  of  serum  used; 
while  the  weight  of  the  dry  residue  shows  the  amount  of 
solid  matter  contained  in  the  same  quantity  of  serum. 

517.  From  the  numbers  now  obtained,  we  are  enabled 
to  calculate  the  proportion  of  the  SOLID  MATTERS  OF  THE 

17 


194:         QUANTITATIVE    ANALYSIS    OF    BLOOD. 

SERUM  in  1000  parts  of  blood,  in  the  following  manner. 
Knowing,  as  we  do,  the  quantity  of  water  in  1000  parts 
of  the  blood  (515);  and  assuming  that  the  water  of  the 
blood  exists  wholly  in  the  form  of  serum;*  knowing  also 
the  proportion  of  water  and  of  solid  matter  contained  in 
the  serum  (516);  we  may,  from  the  quantity  of  water  in 
the  blood,  estimate  the  quantity  of  solids  held  in  solution 
in  the  serum,  thus  : — 

Wt.  of  water!        f  Wt"  °f  solid!        f  Water  in 


71""  matter  in 

in  the  quan- 

«*^fol™  r  :  1  thequanti-  }- :  :  <j 


(Solids 
of  serum 
in  1000 
pts.  of  the 
blood. 


518.  We  have  now  determined  the  proportion  of  water, 
fibrin,  and  solid  matters  of  the  serum,  contained  in  the 
blood,  and  have  only  to  ascertain  the  weight  of  the  COR- 
PUSCLES in  order  to  complete  the  analysis.     This  is  done 
by  adding  together  the  weights  of  the  fibrin  and  the 
solids*  of  the  serum  contained  in  1000  parts  of  blood,  and 
deducting  the  sum  of  them  from  the  weight  of  the  entire 
solid  matter,  which  consists  of  fibrin,  solids  of  the  serum, 
and  corpuscles  ;  the  difference,  therefore,  will  represent 
the  proportion  of  the  latter  in  1000  parts  of  the  blood. 

519.  The  several  results  now  obtained  may  be  recorded 
thus  ;  and  the  numbers,  when  added  together,  should 
amount  to  within  a  fraction  of  1000. 

Water    ........ 

Corpuscles      .  ..... 

Fibrin     ........ 

Solid  matters  of  seruni  ..... 

JLOOO-00 
SECTION   II. 

Quantitative  Analysis  of  Coagulated  Blood,  including  the  esti- 
mation of  the  water,  corpuscles,  fibrin,  and  the  solid  matters 
contained  in  the  serum. 

520.  The  portion  of  blood  intended  for  analysis,  which 
may  consist  of  about  ten  fiuidounces,  should  be  collected 

*  Of  course  this  assumption  introduces  an  error  into  the  analysis, 
since  the  water  belonging  to  the  contents  of  the  globules  is  imputed 
to  the  serum. 


QUANTITATIVE    ANALYSIS    OF    BLOOD.         195 

in  a  weighed  or  counterpoised  glass  beaker,  or  other 
cylindrical  vessel,  and  accurately  weighed;  or  if  it  has 
been  accidentally  collected  in  any  vessel  of  which  the 
weight  has  not  previously  been  determined,  it  may  be 
weighed  as  before,  and  the  weight  of  the  containing 
vessel,  ascertained  after  the  blood  has  been  removed,  de- 
ducted from  the  gross  weight;  the  difference  being,  of 
course,  the  weight  of  the  blood  employed.  The  blood, 
after  being  collected,  is  to  be  set  aside  in  a  tolerably  cool 
place  for  about  twenty-four  hours,  to  allow  it  to  coagu- 
late ;  the  top  of  the  glass  being  covered  with  a  glass  plate 
or  small  dish,  to  preserve  it  from  dust  and  prevent  eva- 
poration. 

521.  About  two  or  three   fluidrachms   of  the   clear 
serum  are  to  be  drawn  off  with  a  pipette,  or  carefully 
poured  off,  into  a  small  weighed  platinum  or  porcelain 
capsule;  after  being  accurately  weighed,  it  is  to  be  eva- 
porated until  it  ceases  to  lose  weight,  on  a  chloride  of 
calcium   bath,   kept   at   a  temperature   of  about  220°. 
When  dry,  the  weight  is  noted ;  the  loss  during  evapo- 
ration representing  the  amount  of  water  in  the  quantity 
of  serum  operated  on,  and  the  weight  of  the  dry  residue 
being  that  of  the  solid  matter  contained  in  the  same.    The 
relative  proportions  of  solid  matter  and  wajer  which  form 
the  serum  are  thus  ascertained. 

522.  While  the  evaporation  of  the  serum  (521)  is  going 
on,  the  examination  of  the  rest  of  the  coagulated  blood 
may  be  proceeded  with.     The  serum  is  first  poured  off 
from  the  clot  with  great  care,  avoiding  the  escape  of  any 
portion  of  the  coagulum ;  the  last  portions  of  the  liquid 
being  removed  by  means  of  a  fine- pointed  pipette,  or  by 
introducing  one  end  of  a  folded  piece  of  bibulous  paper, 
which  will  suck  up  the  liquid  until  it  is  saturated,  and 
may  then  be  replaced  by  another.     This  serum,  although 
it  will  probably  not  be  wanted  for  any  subsequent  expe- 
riments, had  better  be  for  the  present  retained,  in  case  of 
any  accident  happening  to  the  portion  already  taken  for 
evaporation  (521). 

523.  The  clot,  thus  separated  from  the  greater  part  of 
the  serum,  is  now  to  be  divided,  by  means  of  a  sharp 


196         QUANTITATIVE    ANALYSIS    OF    BLOOD. 

knife,  into  two  portions  of  equal  weight  ;*  the  weight  of 
both  being  accurately  made  to  correspond  by  weighing, 
and  adding  or  taking  off  small  slices,  as  necessity  may 
require.  When  this  is  done,  each  portion  will  contain 
one-half  the  fibrin  and  corpuscles  of  the  quantity  of  blood 
operated  on,  together  with  a  certain  amount  of  serum. 
One  of  these  equal  portions  of  the  clot  we  will  call  A, 
and  the  other  B. 

524.  Treatment  of  the  portion  of  clot  A..- — This  is  to  be 
cut  into  thin  shreds  with  a  clean,  sharp  knife,  carefully 
avoiding  any  loss  of  the  fragments  of  the  coagulurn.    The 
finely  sliced  clot  is  then  tied  up  in  a  piece  of  fine  muslin, 
or  calico,  and  washed  under  a  gentle  stream  of  cold  water, 
with  the  assistance  of  occasional  pressure  between  the 
fingers  and  thumb,  until  the  whole  of  the  serum  and  cor- 
puscles are  removed  from  the  interstices  of  the  coagulum, 
and  the  fibrin  is  left  quite  clean  and  colorless.    It  is  then 
taken  out  of  the  muslin,  and  dried  on  a  chloride  of  cal- 
cium bath,  until  it  ceases  to  lose  weight.     The  weight 
thus  obtained  represents  the  fibrin  contained  in  half  the 
clot,  and  when  multiplied  by  two,  gives  the  proportion 
of  FIBRIN  in  the  quantity  of  blood  employed.f 

525.  Treatment  of  the  portion  of  clot  B.— The  weight 
of  the  portion  B  having  been  noted,  it  is  to  be  evaporated 
to  dryness  on  a  chloride  of  calcium  bath  in  a  counter- 
poised or  weighed  capsule.     The  loss  of  weight  which  it 
experiences  during  evaporation,  shows  the  quantity  of 
water  contained  in  half  the  clot,  which,  when  multiplied  by 
two,  gives  the  amount  of  water  present  in  the  entire  clot ; 
while  the  weight  of  the  solid  residue,  also  multiplied  by 
two,  shows  the  quantity  of  solid  matter  which  the  entire 
clot  contains. 

526.  From  the  data  thus  obtained,  we  are  enabled  to 
calculate  the  proportion  of  the  several  constituents,  in 
the  following  manner.     Having  ascertained  the  weight 

*  The  division  must  be  made  vertically,  since  the  horizontal  layers 
of  the  clot  contain  different  proportions  of  the  globules,  being  richer 
towards  the  bottom.  The  exact  equality  of  the  two  parts  of  the 
clot  is  only  necessary  to  save  subsequent  calculation. 

f  To  obtain  an  exact  result,  this  fibrin  should  be  treated  with  ether 
to  remove  fat,  then  with  alcohol,  and  again  dried  and  weighed. 


QUANTITATIVE    ANALYSIS    OF    BLOOD.        197 

of  the  whole  solid  matter  of  the  clot  (525),  which  consists 
of  fibrin,  corpuscles,  and  solids  contained  in  the  portion 
of  serum  with  which  the  clot  is  saturated,  we  first  calcu- 
late how  much  of  the  weight  is  due  to  the  solids  of  the 
serum.  To  do  this,  we  assume  that  the  whole  of  the 
water  present  in  the  clot  is  due  to  serum ;  then,  knowing 
from  a  previous  experiment  (521),  the  relative  propor- 
tions of  water  and  solid  matter  in  the  serum,  and  know- 
ing also  the  quantity  of  water  contained  in  the  clot  (525), 
we  calculate  the  amount  of  solid  matters  in  the  clot, 
which  belong  to  the  serum,  as  follows : — 


'  Wt.  of  water  ] 
in  quantity 
of  serum     V  : 
evaporated.   | 

'  Wt.  of  solid  ] 
matter  in    | 
quantity  of  }•  : 
serum 
evaporated.  J 

fWt.on 
1  water  J 
:  -J  in  the  [  : 
entire 
[   clot.  J 

IWt.  of  solid  ] 
matters  of 
serum  con-     }- 
tained  in   the  J 
entire  clot.    J 

527.  The  weight  thus  calculated,  of  solid  matters  of 
serum  present  in  the  clot,  is  deducted  from  the  weight  of 
the  entire  solid  matter  contained  in  the  clot  (525),  and 
the  difference  will  represent  the  weight  of  the  fibrin  and 
corpuscles.     Having,  therefore,  previously    determined, 
by  a  separate  experiment  (524),  the  amount  of  fibrin,  we 
have  only  to  deduct  that  number,  in  order  to  obtain  the 
proportion   of    CORPUSCLES   in   the   quantity    of  blood 
operated  on. 

528.  Knowing  now  the  amount  of  the  fibrin  and  cor- 
puscles, we  can,  by  deducting  their  combined  weights 
from  that  of  the  entire  blood,  learn  the  quantity  of  serum 
which  it  contained ;  since  the  blood  is  wholly  composed 
of  fibrin,  corpuscles  and  serum. 

529.  From  the  weight  of  serum  thus  obtained,  assum- 
ing that  the  whole  of  the  water  in  the  blood  is  due  to  the 
serum,  we  can  calculate  that  of  the  WATER  and  SOLID 
MATTERS  OF  THE  SERUM  contained  in  the  entire  blood,  in 
the  following  manner,  since  we  have  before  determined, 
by  experiment  (521),  their  relative  proportions: — 

For  the  Water. 

{Wt.of  serum]  f    Loss  of   ]        fWt.  of  serum]  f  Proportion  ] 

which  was    i  t    !    wt.  dur-   I       J    in  quantity   |  J  of  water  in   ! 

evaporated   |  '    j    ing  eva-   ['*]      of  blood      [  :  1  quantity  of  j 

to  dryuess.  J  [poration.  J        [        used.        J  [  blood  used.  J 


198         QUANTITATIVE    ANALYSIS    OF    BLOOD. 

For  the  Solid  Matters  of  the  Serum. 

f   Weight  of    1  fWt.  of  so-]        f  Weight  of]  fWt.  of  solid] 

|  seruin  which  |  |  lid  residue          |   serum  in  I  |    matters  of    I 

-j    was  evapo-    }-  :  •{    of  serum   j- :  :  -j    quantity   }-  :  -j     serum  in 

|  rated  to  dry-  |  j  after  eva-           j    of  blood    J  quantity  of    | 

L        ness.        J  [  poration.  J        ^     used,     j  [  blood  used.  J 

530.  We  shall  now,  therefore,  have  ascertained  the 
proportions  of  the  four  several  constituents  required,  in 
the  quantity  of  blood  employed  in  the  analysis,  viz : — 

Water 

Corpuscles        ....... 

Fibrin       ........ 

Solid  matters  contained  in  the  serum 


which,  when  added  together,  should  amount  very  nearly 
to  the  weight  of  the  blood  used. 

531.  In  order  to  determine  the  proportion  of  the  several 
constituents  present  in  1000  parts  of  the  blood,  the  follow- 
ing calculation  will  in  each  case  be  necessary: — 

f  Wt.  of  blood  ]  f  Weight  of  ]  f  Proportion  of  that  ] 

employed  !  -IAAA  j  each  con-!  J  constituent  in 

j  in  the  '  1  stituent  j  '  |  1000  parts  of  the  f 

analysis.  J  L  obtained.  J  [  blood. 


I 


SECTION  III. 


Quantitative  Analysis  of  Uncoagulated  Blood,  including  the 
determination  of  the  water,  corpuscles,  albumen,  fibrin, 
alcohol  extractive,  water  extractive,  oily  fats,  crystalline  or 
solid  fats,  andjixed  saline  matters. 

532.  The  vessels  required  for  this  analysis  are  nearly 
the  same  as  those  already  described  in  the  shorter  scheme 
of  analysis  (506),  viz : — 

1.  A  six  or  eight-ounce  stoppered  bottle,  the  weight 
of  which  is  accurately  known ;   and  in  which  are 
placed  a  few  small  strips  of  thin  sheet   lead,  the 
weight  of  which  also  is  known. 

2.  A  weighed  platinum  capsule  or  crucible,  capable  of 
holding  rather  more  than  an  ounce  of  liquid;  or,  in 
default  of  this,  a  thin  Dresden  porcelain  crucible,  of 
about  the  same  capacity.     And 


QUANTITATIVE    ANALYSIS    OF    BLOOD.         199 

3.  A  tall  upright  beaker  or  cylindrical  glass,  capable 
of  holding  about  eight  ounces  of  liquid.  The  weight 
of  this  need  not  be  taken. 

533.  The  three  vessels  being  in  readiness,  the  blood  is 
first  to  be  collected.     About  six  ounces  of  the  fluid  are 
allowed  to  flow  into  the  bottle,  which  should  immediately 
be  closed   with   the   stopper,  and  gently  shaken  for  a 
quarter  of  an  hour  or  twenty  minutes,  at  the  end  of 
which  time  the  fibrin  will  be  found  to  have  separated 
from  the  liquid,  and  attached  itself  round  the  fragments 
of  lead.     This  portion  of  blood  we  will  call  A  (536). 

534.  About   an  ounce  of  blood   is   collected   in   the 
weighed  capsule  or  crucible,  and,  after  being  weighed 
for  the  purpose  of  ascertaining  the  exact  quantity  of  blood 
employed,  it  is  placed  on  a  water-bath   or  chloride  of 
calcium  bath,  and  allowed  to  evaporate.     This  portion 
we  will  call  B  (539). 

535.  From  six  to  eight  ounces  of  blood  are  allowed  to 
flow  into  the  beaker,  and  set   aside  to  coagulate  in  a 
tolerably  cool  place  for  about  twenty-four  hours.     This 
portion  we  call  C  (541). 

536.  Treatment  of  the  portion  A. — As  soon  as  the  fibrin 
is  supposed  to  have  separated  completely  from  the  blood, 
and  become  attached  to  the  pieces  of  lead,  the  outside  of 
the  bottle  is  to  be  wiped  clean  and  dry,  and  the  whole  is 
weighed ;    when   the   difference  between    the  combined 
weights  of  the  empty  bottle  and  the  lead,  and  that  of  the 
whole  when  filled,  will  represent  the  quantity  of  blood 
employed  in  the  experiment. 

537.  The  contents  of  the  bottle  are  now  to  be  -emptied 
out  upon  fine  muslin,  in  a  small  evaporating  basin,  and 
the  fibrin  is  to  be  carefully  separated  from  the  fragments 
of  lead,  to  which  it  adheres  loosely.     It  is  then  washed, 
under  a  gentle  stream  of  cold  water,  from  the  serum  and 
corpuscles  with  which  it  is  saturated,  carefully  avoiding 
the  loss  of  any  particles  of  the  fibrin. 

538.  When   quite   clean   and  colorless,  the  fibrin  is 
placed  in  a  platinum  or  thin  porcelain  crucible  of  known 
weight,  and  dried  on  a  chloride  of  calcium  bath,  at  a 
temperature  of  about  220°  or  230°,  until  it  ceases  to  lose 


200         QUANTITATIVE    ANALYSIS    OF    BLOOD. 

weight.*  When  dry,  the  weight  is  noted.  As  the 
fibrin,  in  its  present  state,  contains  traces  of  earthy  phos- 
phates, which  add  slightly  to  its  apparent  weight,  it  may 
now  be  incinerated  in  the  crucible,  until  the  ash  becomes 
white  or  gray.  The  loss  of  weight  which  the  dry  fibrin 
experiences  during  incineration,  represents  the  amount 
of  pure  FIBRIN  in  the  quantity  of  blood  that  was  contained 
in  the  bottle.  The  proportion  present  in  1000  parts  of 
the  blood  may  then  be  calculated  as  follows : — 

{Weight  of )        (Weight  of)  ( Proportion  of   ) 

blood       I  :  4      fibrin      I  :  :  1000  :    J  fibrin  in  1000    I 
employed.  )       (  obtained.  J  (  parts  of  blood.  J 

539.  Treatment  of  the  portion  B. — This  portion  of  the 
blood,  after  being  weighed,  is  allowed  to  remain  on  a 
chloride  of  calcium  bath,  heated  to  about  220°,  until  it 
ceases  to  lose  weight;  when  it  may  be  concluded  that 
the  whole  of  the  water  has  been  expelled.    When  this  is 
the  case  the  weight  is  noted ;  and  the  proportion  of  SOLID 
MATTERS  OF  THE  BLOOD  contained  in  1000  parts  of  the 
fluid  may  be  calculated  as  follows : — 

{Wt.  of  blood  )        f  Weight  of  f  f  Proportion  of  solid  ) 

evaporated    [•  :  •!        dry        I :  :  1000  :  -1     matter  in  1000     I 
to  dryness.  J        (   residue.   J  (     parts  of  blood.     J 

540.  The  dry  residue  (539),  after  being  weighed,  is  to 
be  incinerated  in  the  capsule  or  crucible  until  the  whole 
of  the  charcoal  of  the  organic  matter  is  burnt  away,  and 
the  ash  becomes  of  a  pale  red  color,  f     The  weight  of 
the  ash  tfyus  obtained  shows  the  amount  of  FIXED  SALINE 
MATTER  in  the  quantity  of  blood  evaporated ;  and  from 
this,  the  proportion  contained  in  1000  parts  of  the  blood 
may  be  thus  estimated: — 

f  Weight  of  )       (  Wt.  of  ash  )  C  Proportion  of  fixed  ^ 

•J        blood        [•  :  4    after  in-    [• : :  1000  :  -I     saline  matter  in    [- 
(.  evaporated.  )       (.  cineration.  J  (  1000  pts.  of  blood.  J 


*  For  greater  accuracy,  it  is  well  to  weigh  the  piece  of  muslin,  dried 
at  2200,  before  collecting  the  fibrin  upon  it,  so  as  to  avoid  the  neces- 
sity of  removing  the  fibrin  before  drying. 

f  A  muffle  heated  to  very  low  redness  will  be  found  very  convenient 
for  this  incineration,  which  takes  place  very  slowly  over  a  lamp.  A 
small  charcoal  fire  is  better  than  the  latter. 


QUANTITATIVE    ANALYSIS    OF    BLOOD.        201 

541.  Treatment  of  the  portion  G. — This  portion  of  blood 
is  allowed  to  stand  for  about  twenty -four  hours,  in.  order 
that  it  may  coagulate  spontaneously,  and  divide  itself 
into  a  firm  clot  and  perfectly  clear  serum. 

542.  Two  or  three  fluidrachms  of  the  serum  are  first 
removed  from  the  surface  and  placed  in  a  small  platinum 
or  porcelain  capsule,  the  exact  quantity  of  serum  taken 
being  ascertained  by  again  weighing  the  capsule  and  its 
contents.     It  is  then   placed  on  a  chloride  of  calcium 
bath,  and  when  perfectly  dry,  again  weighed,  in  order  to 
determine  the  relative  proportions  of  solid  matter  and 
water  in  the  serum ;  the  weight  of  the  dry  residue  and 
the  amount  of  loss  during  evaporation  representing  re- 
spectively the  proportion  of  solids  and  of  water  in  the 
quantity  of  serum  employed. 

543.  From  the  numbers  thus  obtained,  we  are  able 
(assuming  that  the  whole  of  the  water  in  the  blood  exists 
in  the  form  of  serum)  to  estimate  the  quantity  of  SERUM 
contained  in  1000  parts  of  the  blood,  since  we  have  before 
ascertained  the  amount  of  water  in  1000  parts  of  blood 
(539),  and  also  the  relative  proportion  which  the  serum 
bears  to  the  water  contained  in  it  (54:2),  thus: — 


"Wt.  of  water] 
in  the  quan- 
tity of  serum  ! 
that  was      f 
evaporated    j 
to  dryness.  J 

f  Weight  of] 
serum 
J  which  was  j 
'    ]     evapo-     f  '  ' 
rated  to    j 
[  dryness.  J 

Weight  of] 
water 
in  1000 
parts  of 
of 
blood.     J 

"Weight  of] 
serum 
in  1000 
parts 
of 
blood.     J 

544.  Another   portion  of  the  clear  serum,  weighing 
exactly  500  grains,  is  now  to  be  weighed  out  in  a  plati- 
num or  porcelain  capsule,  and  evaporated  to  dryness  on 
a  water-bath.     This  will  serve  for  the  estimation  of  the 
albumen,  oily  and  crystalline  fats,  and  alcohol  and  water 
extractives. 

545.  The  dry  residue  is  to  be  detached,  with  the  aM 
of  a  knife,  from  the  capsule,  and  reduced  to  fine  powder 
in  a  mortar.     As  it  is  impossible  to  effect  this  without 
loss  the  weight  of  the  powder  must  be  ascertained.    <-A 
small  light   flask   (perfectly   dry)  is   weighed,   and   the 
powder  introduced  into  it,  the  increase  of  weight  being 
noted.     Half  an  ounce  of  ether  is  then  poured  into  the 


202          QUANTITATIVE    ANALYSIS    OF    BLOOD. 

flask,  and  a  gentle  heat  applied  by  a  water-bath*  for 
about  ten  minutes,  when  it  may  be  carefully  poured  off 
and  replaced  by  a  fresh  portion. 

546.  The  ethereal  solution  thus  obtained,  containing 
the  fatty  matters,  both  oily  and  crystalline,  is  to  be  eva- 
porated in  a  capsule  of  known  weight,  on  a  water-bath, 
until  the  whole  of  the  ether  is  expelled.  The  residue  is 
now  weighed,  by  which  the  whole  amount  of  fatty  matters 
is  ascertained.  It  is  then  treated  with  cold  alcohol, 
which  will  dissolve  out  the  oily  fat.  The  weight  of  the 
residue  left  on  evaporating  the  alcoholic  solution,  there- 
fore, will  represent  the  amount  of  OILY  FAT  in  the  serum ; 
and  the  difference  between  this  and  the  weight  of  the 
whole  fatty  matter  shows  the  quantity  of  SOLID  OR  CRYS- 
TALLINE FATTY  MATTER  in  the  same  serum..  The  propor- 
tion of  each  of  these,  which  is  contained  in  1000  parts  of 
blood,  may  then  be  calculated  as  follows : — 

f  Wt.  of  solid  1        f  Weight  of  ]        f  Total  solid  ]        f  Fatty  mat-  1 

j     residue  of    I    .    J        fatty      '        !     from  500    !        I     ter  in  500    I 

serum        j    '    /     matter      \ '      \      grs.  of      \        \        grs.  of 


I    .    !        fatty      I'     from  50 
f    '    /     matter  '  j      grs.  of 

J        [_  obtained.  J        [_     serum. 


OC31  HUB  I  AllCittCi.  ;_!.>.    VFi 

^   employed.  J        [_  obtained.  J        [_     serum,    j        l_      serum.       J 
*  For  the  Oily  Fat. 

{Wt.  of  oily   1        (  Wt.  of  serum  )        (  Proportion  of  oily  ^) 
fat  in  500      [• :  :  -I  in  1000  parts  V  :  \  fat  in  1000  parts  of  I 
grs.  of  serum.  J       {.      of  blood.      J       (.  blood.  J 

For  the  Crystalline  Fatty  Matter. 

{Wt.  of  crystal- 1  (  Wt.  of  serum  \  (  Proportion  of  crys-  ) 
line  fat  in  500  [•:  :  \  in  1000  parts  I  :  -I  talline  fat  in  1000  [ 
grs.  of  serum.  J  (  of  blood.  J  (  parts  of  blood.  J 

547.  The  residue  which  proved  insoluble  in  the  ether 
(545),  is  now  to  be  warmed,  in  order  to  expel  any  traces 
of  ether  that  may  still  be  present,  and  then  treated  with 
water  which  is  gradually  heated  to  boiling,  this  will 
coagulate  the  albumen,  thus  rendering  it  insoluble ;  while 
the  extractive  matters  are  dissolved  out  (549).  The  mix- 
ture is  then  filtered  through  a  dried  and  weighed  filter, 
and  the  insoluble  residue  of  albumen  washed  on  the  filter 
with  hot  water,  until  a  drop  of  the  filtered  liquid  causes 

*  The  flask  should  be  fitted  with  a  cork  carrying  a  glass  tube  about 
three  feet  long  and  a  quarter  of  an  inch  in  diameter,  to  diminish  the 
loss  of  ether  by  evaporation. 


QUANTITATIVE    ANALYSIS    OF    BLOOD.        203 

no  precipitate,  or  merely  a  very  slight  opalescence,  when 
tested  with  a  solution  of  nitrate  of  silver. 

548.  The  albumen,  thus    freed  from  extractive  and 
solable  saline  matters,  is  to  be  dried  and  weighed ;  but 
as  some  traces  of  inorganic  matter  are  always  associated 
with  the  albumen,  the  dry  mass  is  to  be  incinerated,  and 
the  weight  of  the  ash  deducted  from  it;  when  the  differ- 
ence will  represent  the  amount  of  pure  ALBUMEN  in  the 
serum.     The  proportion  in  1000  parts  of  blood  may  then 
be  calculated  thus: — 

{Wt.  of  solid  ]  C  Weight  of]  f  Total  solid  ]        f  Albumen  ] 

residue  of    !  J   albumen   I  J    from  500    II     in  500     ! 

serum  j  obtained.  f  grs.  of      j    '    j-  grs.  of     f 

employed.  J  [                    j  [     serum.    J        [   serum,    j 

f   Wt.  of  albu-   )        f  Wt.  of  serum  )        f  Proportion  of  albu-  ) 

500  :  \  men  in  500  grs.  I :  :\  in  1000  parts  [•  :  \  men  in  1000  parts  f 

(      of  serum.      )       [     of  blood.     J       (          of  blood.         J 

549.  The  aqueous  solution  filtered  from  the  albumen 
(547),  containing  the  extractive  matters  and  soluble  salts, 
is  now  to  be  evaporated  to  dryness  in  a  capsule  of  known 
weight,  on  a  water-bath,  and  weighed.     The  dry  residue 
is  then  treated  with  alcohol,  which  should  be  poured  off 
and  renewed  as  long  as  anything  continues  to  be  dissolved 
by  it.     The  alcoholic  solution  is  evaporated  to  dryness 
on  a  water-bath,  and  weighed ;  it  is  then  incinerated,  and 
the  weight  of  the  ash  is  deducted  from  that  of  the  dry 
mass  previous  to  incineration.    The  number  thus  obtained 
represents  the  amount  of  ALCOHOL  EXTRACTIVE  in  500  grs. 
of  serum,  which  may  be  reduced  to  the  proportion  in  1000 
parts  of  blood  by  a  calculation  similar  to  the  above. 

550.  The  portion  of  the  dry  residue  which  proved  in- 
soluble in  alcohol  (549),  is  now  to  be  dried,  weighed,  and 
ignited ;  the  weight  of  the  ash  being  deducted  from  that 
of  the  dry  mass  previous  to  ignition.     This  will  give  the 
weight  of  the  WATER  EXTRACTIVE  in  500  grs.  of  serum  ; 
from  which  the  quantity  in  1000  parts  of  blood  may  be 
estimated  as  in  the  former  cases : — 

f  Wt.  of  water  ^        f  Wt.  of  serum  ]       f  Proportion  of  water  ] 

500  :  \  extract,  in  500  j> :  :  4  in  1000  parts  V  :   3     extract,  in  1000     J> 

t  grs.  of  serum.  J        [      of  blood.      J        [     parts  of  blood.     J 

551.  We  shall  now  have  estimated  the  proportion  of 


204:         QUANTITATIVE    ANALYSIS    OF    BLOOD. 


water  and  of  all  the  solid  constituents,  with  the  exception 
of  the  CORPUSCLES.  The  proportion  of  these  is  known  by 
deducting  the  sum  of  the  several  solid  matters,  the  weights 
of  which  are  already  determined  (including  everything 
but  the  corpuscles),  from  the  weight  of  the  whole  solid 
matter  contained  in  1000  parts'of  blood  (539),  ihe  differ- 
ence representing  the  proportion  of  corpuscles  present 
in  1000  parts  of  the  fluid. 

552.  The  results  of  the  analysis  may  then  be  recorded 
as  follows,  and  should,  when  added  together,  amount  to 
a  fraction  less  than  1000. 

Water       . 

Corpuscles 

Albumen  . 

Fibrin 

Alcohol  extractive 

Water  extractive 

Oily  fats  . 

Crystalline  or  solid  fats 

Fixed  saline  matter  . 


SECTION  IV. 

Quantitative  Analysis  of  Coagulated  IHood,  including  the  esti- 
mation of  the  ivater,  corpuscles,  albumen,  fibrin,  alcohol 
extractive,  water  extractive,  oily  fats,  crystalline  or  solid  fats, 
and  fixed  saline  matters. 

553.  About  ten  or  twelve  ounces  of  blood  having  been 
collected  in  a  beaker,  or  other  rather  tall  vessel  of  known 
weight,  it  is  to  be  covered  over  to  prevent  evaporation, 
and  set  aside  in  a  cool  place  for  about  twenty-four  hours, 
when  it  will  be  found  to  have  separated  into  a  firm  clot 
and  clear  serum.  The  weight  of  the  whole  blood  is  to 
be  accurately  determined  either  before  or  after  coagu- 
lation. Three  or  four  fluidrachms  of  the  clear  serum 
are  first  drawn  off  with  a  pipette,  weighed  in  a  platinum 
or  porcelain  crucible  of  known  weight,  evaporated  to 
dryness  on  a  chloride  of  calcium  bath,  and  the  weight  of 
the  dry  residue  ascertained.  The  loss  of  weight  during 
evaporation  representing  the  water,  we  thus  determine 


QUANTITATIVE    ANALYSIS    OF    BLOOD.         205 

the  relative  proportions  of  SOLID  MATTER  AND  WATER  IN 

THE  SERUM. 

554.  The  dry  residue  of  the  serum  (553),  is  now  to  be 
incinerated,  until  the  ash  becomes  white  or  gray;  and 
the  latter  is  then  weighed.     The  proportion  of  FIXED 
SALINE  MATTER  OF  THE  SERUM  is  thus  ascertained. 

555.  The  greater  part  of  the  remaining  clear  serum  is 
now  to  be  carefully  poured  off  from  the  coagulum,  and, 
retained  for  further  examination  (565).     The  last  por- 
tions of  the  liquid  are  to  be  removed  by  means  of  a  fine 
pipette,  or  by  sucking  it  up  with  little  rolls  of  bibulous 
paper  (522),  carefully  avoiding  the  removal  of  any  por- 
tions of  the  clot. 

556.  The  coagulum,  thus  separated  as  completely  as 
possible  from  the  serum,  is  now  to  be  divided  vertically 
into  two  portions  of  exactly 'equal  weight  (523),  each  of 
which  will  then  contain  one  half  of  the  fibrin  and  cor- 
puscles present  in  the  quantity  of  blood  operated  on, 
together  with  a  certain  amount  of  serum.     These  two 
equal  portions  of  clot  we  will  distinguish  as  A  and  B. 

557.  Treatment  of  the  portion  of  clot  A. — This  portion  of 
the  clot  is  to  be  cut  with  a  sharp  knife  into  fine  slices, 
carefully  avoiding  any  loss.     These  are  then  tied  up  in 
a  piece  of  fine  muslin,  and  washed,  until  they  become 
quite  colorless,  when  it  maybe  concluded  that  the  whole 
of  the  corpuscles  and  serum  has  been  washed  out.     The 
fibrin  is  now  dried  on  a  chloride  of  calcium  bath  at  a 
temperature  of  about  230°,  and  weighed.     It  still,  how- 
ever, contains  traces  of  earthy  salts,  the  quantity  of  which 
is  known  by  incinerating  the  dry  fibrin,  and  deducting 
from  it  the  weight  of  the  ash.    The  loss  of  weight  during 
incineration  represents  the  quantity  of  fibrin  contained 
in  one  half  the  clot,  and  this,  when  multiplied  by  two, 
gives  the  proportion  of  FIBRIN  in   the  quantity  of  blood 
employed. 

558.  Treatment  of  the  portion  of  dot  B. — This  half  of  the 
clot  is  to  be  weighed  in  a  capsule  of  known  weight,  and 
evaporated  to  dryness  on  a  chloride  of  calcium  bath. 
The  residue  is  now  weighed,  and   the  loss   of  weight 
during  evaporation  will  show  the  amount  of  water  pre- 
sent in  half  the  clot;  which,  when  multiplied  by  two, 

18 


206          QUANTITATIVE    ANALYSIS    OF    BLOOD. 

gives  the  quantity  of  WATER  CONTAINED  IN  THE  ENTIRE 
CLOT  ;  while  the  weight  of  the  dry  residue,  also  multi- 
plied by  two,  represents  the  amount  of  SOLID  MATTER 

PRESENT  IN  THE  ENTIRE  CLOT. 

The  dry  residue  of  B  is  to  be  retained  for  subsequent 
incineration  (563). 

559.  Having  thus  determined  the  weight  of  the  whole 
.  solid  matter  of  the  clot,  which  consists  of  fibrin  and  cor- 
puscles, together  with  the  solids  contained  in  the  portion 
of  serum  with  which  the  clot  is  saturated;  we  now  have 
to  calculate  how  much  of  the  weight  is  due  to  the  solids 
of  the  serum.  Assuming  that  the  whole  of  the  water 
present  in  the  clot  is  due  to  the  serum,  and  knowing  the 
relative  proportions  of  water  and  solid  matter  in  the 
serum  (553);  knowing  also  the  quantity  of  water  present 
in  the  entire  clot  (558);  the  amount  of  solid  matters  in 
the  clot  which  belong  to  the  serum  may  be  calculated  in 
the  following  manner  : — 


'  Wt.  of  water  "| 

fWt.  of  solid") 

r 

Wt.  of  "I 

f    Wt.  of  solid    1 

in  quantity 

1 

1 

matter  in 

i 

water     j 

|    matters  of  se- 

of  serum 

h 

j 
1 

quantity  of 

J 

H 

in  entire  [•  : 

-{  rum  contained  }• 

evaporated. 

I 

serum  evap. 

clot. 

|     in  the  entire    j 

j 

I 

3 

I 

J 

L           clot.           J 

560.  The  weight  of  solid  matters  of  the  serum  thus 
found  to  be  present  in  the  clot,  is  to  be  deducted  from 
the  weight  of  the  entire  solid  matter  of  the  clot  (558), 
when  the  difference  will   represent  the  weight  of  the 
fibrin  and  corpuscles;  the  weight  of  the  fibrin,  however, 
having  been   already  ascertained  by  a  separate  experi- 
ment (557),  we  have  merely  to  deduct  that  amount,  in 
order  to  determine  the  proportion  of  CORPUSCLES  in  the 
quantity  of  blood  employed  in  the  analysis. 

561.  Now,  since  the  blood   may  be  said   to  consist 
wholly  of  fibrin,  corpuscles,  and  serum ;  and  knowing,  as 
we  do  (557,  560),  the  weight  of  the  fibrin  and  corpuscles ; 
we  can,  by  deducting  the  combined  weights  of  those  two 
substances  from  the  weight  of  the  entire  blood,  learn  the 
proportion  of  SERUM  iii  the  quantity  of  blood  operated 
upon. 

562.  But  we  have  before  determined  the  relative  pro- 
portions of  solid  matter  and  water  in  the  serum  (553) ;  so 


QUANTITATIVE    ANALYSIS    OF    BLOOD.         207 


:  : 

'  Wt.  of  serum  ] 
in  quantity 
of  blood       [  :  - 

used. 

Proportion  ] 
of  water  in  j 
quantity  of  }- 
blood 
used.      J 

that,  assuming  that  the  whole  water  of  the  blood  is  due 
to  the  serum,  we  can,  from  the  quantity  of  serum  obtained 
in  paragraph  561,  estimate  the  proportion  of  WATER  in 
the  blood,  thus : — 

Wt.  of    "|      floss  of  wt. 

seruin        |  during 

which  was   >  :  •     evapora- 
evaporated  tioii 

^todryness.  J  (water). 

563.  The  dry  residue  of  the  portion  of  the  clot  B  (558), 
is  now  to  be  incinerated.  The  weight  of  the  ash  thus 
obtained,  multiplied  by  two,  will  give  the  amount  of  the 
inorganic  salts  contained  in  the  clot.  A  certain  portion 
of  this  weight,  however,  is  due  to  the  salts  of  the  serum 
which  was  contained  in  the  clot,  the  amount  of  which 
may  be  learnt  by  the  following  calculation,  since  we  have 
before  determined  the  relative  proportions  of  solid  matter 
and  inorganic  ash  in  the  serum  (553,  554). 


Wt.  of  solid  mat-  1 
ter  in  quantity    | 
of  serum  evapo-  }•  :  - 
rated  to  dry-     1 
ness.            J 

fWt.ofash] 
derived    | 
from  same  f  : 
quantity 
of  serum.  J 

fWt.of  solid] 
1     matters 
:  •{    of  serum    }•  :  - 
in  the 
L       clot.        J 

IWt.ofashl 
do  rived 
from  the    }• 
serum  in    | 
the  clot.  J 

By  deducting  this  number  from  the  weight  of  the  ash  of 
the  whole  clot,  we  ascertain  the  amount  of  inorganic  sa- 
line matter  derived  from  the  fibrin  and  corpuscles. 

564.  In  order  to  determine  the  whole  amount  of  fixed 
salts  in  the  blood,  we  must  now  reckon  how  much  the 
whole  of  the  serum  contains.     This  is  done  as  follows: — 

f    Weight  of    ]  fWt.  of  ash]        f  Wt.  ofse-"]  fWt.  of  fixed] 

j  serum  evapo-  I  .  J  from  same  i  .  .  j    rum.  in     I  .  J      salts  in 

1       rated  to       |  I    quantity    J     '  1  the  entire  f  '    |    the  whole    | 

[     dryness.      J  [of  serum.  J        [     blood.     J  [_      serum,      j 

By  adding  together  the  ash  of  the  serum  thus  obtained, 
and  that  derived  from  the  fibrin  and  corpuscles  (563),  we 
ascertain  the  proportion  of  FIXED  SALINE  MATTER  in  the 
quantity  of  blood  employed  in  the  analysis. 

565.  Estimation  of  the  albumen,  extractives,  and  fatty  mat- 
ters.— Five  hundred  grains  of  the  clear  serum  (555),  are 
to  be  weighed  out  in  a  platinum  or  porcelain  evaporating 
basin,  and  evaporated  to  dry  ness  on  a  water  bath.  The  resi- 
due is  then  treated  as  described  in  paragraphs  545 — 550. 


208         QUANTITATIVE    ANALYSIS    OF    BLOOD. 

566.  The  results  of  the  analysis  may  then  be  summed 
up  as  follows ;  and  if  the  experiments  have  been  conducted 
with  care,  the  numbers  will,  when  added  together,  coin- 
cide very  nearly  with  the  whole  quantity  of  blood  em- 
ployed in  the  analysis. 

Water 

Corpuscles    ........ 

Albumen ........ 

Fibrin       ........ 

Alcohol  extractive    ...... 

Water  extractive      ...... 

Oily  fats  .  - 

Crystalline  or  solid  fats     ..... 
Fixed  saline  matters         ..... 


567.  In  order  to  reduce  these  several  amounts  to  the 
proportion  contained  in  1000  parts  of  the  blood,  the  fol- 
lowing calculation  must  be  made  in  each  case: — 

{Wt.  of  I  f  Wt.  of  each  ^|        f  Proportion  of  that  con-  ^ 

blood  V  :  1000  :  :  <j  constituent  j.  :   \   stituent  in  1000  parts   \ 
used.  J  I   obtained.  J        [  of  blood.  J 

The  several  quantities  thus  obtained  should,  when  added 
together,  amount  to  a  fraction  less  than  one  thousand. 

SECTION  V. 
Average  Composition  of  Healthy  Blood. 

568.  The  following  analyses  .will  serve  to  show  the 
usual  composition  of  healthy  blood  in  1000  parts. 


QUANTITATIVE    ANALYSIS    OF    BLOOD.        209 


569.  Analysis  I. 
f  Fibrin 


Healthy  Venous  Blood.    (Dumas.) 


130  Clot 


Globules 


)  Albuminous  matter 


870  Serum 


;i 


1000 


f  Water       . 

Albumen . 

Oxygen    . 

Nitrogen  . 

Carbonic  acid 

Extractive  matter     .... 

Phosphorized  fat 

Cholesteriu       ..... 

Serolin      ...... 

Oleic  and  margaric  acids  .         .         . 

Chlorides  of  sodium  and  potassium  . 

Muriate  of  ammonia 

Carbonate  of  soda,  lime,  and  magnesia 

Phosphates  of  soda,  lime,  and  magnesia 

Sulphate  of  potash   .... 

Lactate  of  soda          .... 

Salts  of  the  fatty  acids      . 
[  Yellow  coloring  matter     . 


570.  Analysis  II.   (Simon.) 


3 

2 
125 

790 
70 


10 


1000 


Water 

Fibrin 

Fat  . 

Albumen 

Globulin 

Hnematin 

Extractive  matter  and  salts 

571.  Analyses  III  and  IV. 
Showing  the  mean  composition 


795-278 
2-104 
2-346 
76-600 
103-022 
6-209 
12-012 

(Becgiierel  and  Rodier.) 
<>f  Mule  and  Female  Blood. 


Density  of  defibrinated 
Density  of  serum  . 
Water 
Fibrin 

blood 

Male. 
.  1060-00 
.  1028-00 
.     779-00 
2-20 

Female. 
1057-50 
1027-40 
791-10 
2-20 

Fatty  matters     . 
Serolin   . 
Phosphorized  fat 
Cholesterin 
Saponified  fat 

. 

1-60 
0-02 
0-49 
0-09 
1-00 
09-40 

1-62 
0-02 
0-46 
0-09 
1-04 
70-50 

Blood-corpuscles   . 
Extractive  matters  and 
Chloride  of  sodium 
Other  soluble  salts 
Earthy  phosphates 
Iron    . 

salts 

is*  ' 

.     141-10 
6-80 
3-10 
2-50 
0-33 
0-57 

127-20 
7-40 
3-90 
2-90 
0-35 
0-54 

210 


MORBID    BLOOD. 


572.   Analysis  V.    (Lehmann.) 
Blood-corpuscles. 

Water 688-00 

Solid  constituents  .  .  312-00 


Specific  gravity  . 
Hsematiu 

Hsemato-crystallin . 
Cell-membranes 
Fat          . 

Extractive  matter  . 
Mineral    substances 

Iron)  . 


(exclusive   of 


•0885 

16-75  Fibrin 
241-07  Albumen 

41-15 
,       2-31 
2-60 

8-12 


Liquor  sanguiuis. 
902-90 
97-10 
1-028 
4-05 
78-84 


1-72 
3-94 

8-55 


Chlorine 
Sulphuric  acid 
Phosphoric  acid 
Potassium 

Sodium  .... 
Oxygen  .... 
Phosphate  of  lime 
Phosphate  of  magnesia  . 


1-686 
0-066 
1-134 
3-328 
1-052 
0-667 
0-114 
0-073 


3-644 
0-115 
0-191 
0-323 
3-341 
0-403 
0-311 
0-222 


573.  Analysis  VI.    (Endcrlin.) 
Showing  the  Composition  of  the  Ash  of  Human  Blood. 

Tribasic  phosphate  of  soda  (3NaO,P05)  22-100 

Chloride  of  sodium .         .  54-769 

Chloride  of  potassium     .  4-416 

Sulphate  of  potash  .  2-461 

Phosphate  of  lime  .         .  3-636 

Phosphate  of  magnesia   .  0-769 

Peroxide  of  iron  and  phosphate  of  iron  10-770 

98-921 


Eecent  analyses  have  proved  that,  as  would  be  expected, 
the  quantitative  composition  of  the  blood  varies  with  the 
part  of  the  circulation  from  which  it  is  drawn. 


CHAPTER   III. 

MORBID  BLOOD. 


574.  THE  chemistry  of  the  blood  in  its  pathological 
conditions,  has,  until  within  the  last  few  years,  occupied 
very  little  attention  from  the  chemist  or  physician ;  the 


MORBID    BLOOD.  211 

consequence  of  which  has  been,  that  much  ignorance  has 
always  prevailed,  and,  it  is  to  be  feared,  still  prevails, 
among  the  great  mass  of  the  profession;  respecting  this 
important  and  interesting  subject  of  inquiry.  It  is  not 
unreasonable  to  anticipate  that  the  fresh  knowledge  which 
we  are  now  almost  daily  acquiring  in  this  and  other 
kindred  branches  of  physiological  and  pathological  chem- 
istry, will  gradually  lead  to  highly  important  and  bene- 
ficial practical  results,  in  the  more  enlightened  treatment 
of  disease,  and  the  more  ready  mitigation  of  suffering. 

575.  The  variations  which  are  found  to  occur  in  the 
chemical  composition  of  morbid  blood  may  be  divided 
into  two  r classes : — 

1st.  Those  in  which,  so  far  as  we  are  aware,  no  abnor- 
mal matter,  not  contained  in  healthy  blood,  is  present; 
but  in  which  one  or  more  of  the  normal  constituents 
of  healthy  blood  exists  in  a  greater  or  less  propor- 
tion than  in  the  healthy  fluid. 

2d.  Those  in  which  we  can  detect  the  presence  of  one 
or  more  abnormal  matters  which  are  not  found  in 
healthy  blood. 

576.  To  the  first  of  these  classes  belong  those  cases  in 
which  we  find  an  excess  or  deficiency  of  water,  corpus- 
cles, albumen,  fibrin,  fatty  matters,  cholesterin,  urea,  uric 
acid,  or  inorganic  salts;  and  to  the  second,  those  in  which 
either  sugar,  biliary  matter,  pus,  entozoa,  or  other  abnor- 
mal matter,  can  be  detected.     I  will  briefly  notice  each 
of  these  morbid  conditions  of  the  blood,  together  with 
the  mode  of  examination,  whether  chemical  or  micro- 
scopic, which  will  be  found  most  readily  applicable  to 
each. 


CLASS   I. — Morbid  Blood  in  which   no    abnormal  matter  is 

present. 

SECTION  I. 
Blood  containing  an  excess  or  dejiciency  of  Water. 

577.  The  proportion  of  water  even  in  healthy  blood 
appears  to  vary  considerably,  so  that  it  is  difficult  to  say 


212  MORBID    BLOOD. 

what  may  be  considered  as  the  normal  amount.  The 
usual  average,  however,  contained  in  human  blood,  seems 
to  be  from  790  to  800  in  1000  parts. 

578.  In  some  forms  of  disease,  as,  for  example,  anaemia 
and  chlorosis,  the  proportion  of  water  is  usually  much 
greater,  and  has  been  known  to  amount  to  upwards  of 
900  parts  in  1000.     In  certain  other  pathological  condi- 
tions, on  the  contrary,  the  blood  is  found  to  contain  con- 
siderably less  water  than  is  present  in  the  healthy  fluid ; 
in  cholera,  for  instance,  where  the  blood  is  so  rich  in  solid 
matter  as  almost  to  resemble  jelly  in  appearance,  it  has 
been  known  to  contain  not  more  than  480  parts  of  water 
in  1000. 

579.  The  proportion  of  water  present  in  any  specimen 
of  blood  may  readily  be  ascertained,  by  evaporating  a 
known  weight  of  the  fluid  in  a  weighed  or  counterpoised 
capsule,  on  a  chloride  of  calcium  bath,  heated  to  about 
220°  or  230°,  until  it  ceases  to  lose  weight.     The  loss  of 
weight  during  the  evaporation  will  then  represent  the 
proportion  of  water  in  the  quantity  of  blood  employed, 
which  may  be  reduced  to  1000  parts,  as  follows: — 

evapoTa^ed.  J    '  {  durinS  evapofation.  j  : :       )0  j  p™erQfi: 

SECTION  II. 
Blood  containing  an  excess  or  deficiency  of  Corpuscles. 

580.  The  average  proportion  of  corpuscles  contained 
in  healthy  human  blood  appears  to  be  from  120  to  130 
parts  in  1000.     In  disease,  especially  in  some  forms  of 
fever,  it  sometimes  increases  considerably,  and  has  been 
known  to  amount  to  185  parts  in  1000;  while  inanasmia, 
and  certain  other  affections  long  known  as  being  attended 
with  great  poorness  of  blood,  the  proportion  of  corpuscles 
frequently  does  not  amount  to  more  than  60  or  70,  and 
has  been  known  to  be  as  low  as  21,  in  1000  parts. 

581.  The  direct  determination  of  the  weight  of  the 
corpuscles  is  a  matter  of  considerable  difficulty,  so  that 
they  are  generally  estimated  by  deducting  the  combined 
weights  of  the  water,  fibrin,  and  solid  matters  of  the 


MORBID    BLOOD.  213 

serum,  which  are  easily  determined  experimentally,  from 
that  of  the  entire  blood,  in  the  manner  described  in  para- 
graphs 518,  527,  &c. 

582.  According  to  Figuicr,  their  weight  may  be  deter- 
mined with  considerable  accuracy  by  mixing  the  blood, 
previously  defibrinated  by  agitation  with  fragments   of 
lead  (507),  and  weighed,  with  about  eight  times  its  bulk 
of  a  saturated  solution   of  sulphate   of  soda,  filtering 
through  a  filter  of  known  weight,  and  washing  the  cor- 
puscles on  the  filter  with  a  little  more  of  the  saline  solu- 
tion (456).    When  most  of  the  liquid  has  drained  through, 
the  filter  with  its  contents  is  dipped  in  boiling  water,  and 
allowed  to  remain  in  it  some  little  time,  in  order  to  dis- 
solve out  the  salt;  while  the  organic  matter  of  the  cor- 
puscles is  coagulated  by  the  heat,  and  thus  rendered 
insoluble.     The  filter,  with  the  corpuscles,  is  then  dried 
at  212°,  weighed,  and  the  weight  of  the  dry  filter,  pre- 
viously determined,  being  deducted,  the  difference  will 
represent  the  weight  of  the  corpuscles  contained  in  the 
quantity  of  blood  operated  on. " 

583.  The  microscopic  appearance  of  the  corpuscles  is 
also  not  unfrequently  found  to  vary  under  the  influence 
of  disease,  the  modifications  of  form  occurring  occasion- 
ally in  the  living  body,  but  more  frequently  after  death. 
Most  of  these  changes  are  due  to  the  phenomena  of  en- 
dosmosis  or  exosmosis  already  referred  to  (456).     Thus 
they  are  sometimes  met  with  having  a  more  or  less  glo- 
bular form,  owing  to  the  entrance  of  fluid  less  dense  than 
the  serum  of  healthy  blood;  at  other  times   they  are 
found  to  have  a  wrinkled  or  indented  outline,  similar  to 
that  which  the  healthy  corpuscle  assumes  when  placed 
in  contact  with  strong  saline  solutions  of  high  specific 
gravity.     (See  Fig.  65.) 

584.  In  examining  the  blood-corpuscles  under  the  mi- 
croscope with  a  view  to  detecting  any  abnormal  appear- 
ance as  a  consequence  of  disease,  it  must  be  borne  in 
mind  that  these  and  other  analogous  changes  in  the  form 
of  the  corpuscle  are  artificially  induced  by  the  action  of 

.water  or  other  liquids  with  which  they  may  have  been 
allowed  to  come  in  contact;  such  contact  should  therefore 
be  carefully  avoided.  The  wrinkled  appearance  is  some- 


214  MORBID    BLOOD. 

limes  caused  also  by  the  concentration  of  the  serous  fluid, 
owing  to  spontaneous  evaporation  (456). 

SECTION  III. 
Blood  containing  an  excess  or  deficiency  of  Albumen. 

585.  The  average  proportion  of  albumen  in  healthy 
blood  appears  to  lie  between  70  and  75  parts  in  1000; 
while  in  disease  it  is  occasionally  (as  in  cholera)  as  high 
as  131}  and  (as  in  Bright's  disease)  as  low  as  55  parts  in 
1000. 

586.  The  amount  of  albumen  in  any  specimen  of  blood 
may  be  ascertained  in  the  manner  described  in  paragraph 
547 ;  or  a  weighed   portion  of  serum   may  be  carefully 
neutralized  with  dilute  hydrochloric  acid,  diluted  with 
an  equal  bulk  of  water,  and  boiled  for  about  a  quarter 
of  an  hour.     The  coagulum  of  albumen  is  then  separated 
by  filtration,  dried  at  212°,  and  treated  with  hot  ether  to 
remove  the  fat  (545),  and  weighed  before  and  after  inci- 
neration ;  the  difference  between  the  two  weighings  being 
the  weight  of  albumen  in  the  quantity  of  serum  used  (548). 

587.  The  quantitative  estimation  of  the  other  consti- 
tuents of  the  blood  may,  if  necessary,  be  conducted  as  in 
the  case  of  healthy  blood  (503,  &c). 

SECTION  IV. 
Blood  containing  an  excess  or  deficiency  of  Fibrin. 

588.  Healthy  human  blood  usually  contains  from  two 
to  three  parts  of  fibrin  in  1000 ;  while  in  disease  it  has 
been  found  to  vary  from  a  mere  trace,  to  upwards  of  ten 
parts  in  1000 ;    a  considerable  increase  in  the  amount 
being  usually  found  in  most  forms  of  inflammatory  dis- 
ease. 

589.  The  peculiar  appearance  frequently  to  be  seen 
after  coagulation,  in  blood  taken  from  the  body  during 
certain  pathological  conditions,  long  known  as  the  huffy 
coat,  is  caused  by  the  upper  portion  of  the  clot  being 
composed  almost  entirely  of  fibrin,  or  of  some  modifica- 
tion of  protein  closely  allied  to  it,  unmixed  with  the  red 
corpuscles.     This  may  be  owing  either  to   the   blood- 


MORBID    BLOOD.  215 

corpuscles  subsiding  in  the  liquid  more  rapidly  than  in 
ordinary  blood,  or  to  the  fibrin,  coagulating  more  slowly; 
in  either  case  the  upper  portion  of  the  coagulated  fibrin 
would  be  more  or  less  free  from  the  corpuscles  to  which 
the  red  color  of  the  ordinary  clot  is  due.  The  blood  in 
which  the  buffy  coat  is  found  to  occur  is,  in  most  cases, 
rather  rich  in  fibrin,  and  it  was  formerly  regarded  as  a 
sure  sign  of  inflammation ;  an  opinion  which  has  since 
been  proved  to  be  altogether  erroneous  (452). 

590.  The  proportion  of  fibrin  may  be  readily  deter- 
mined either  in  coagulated  or  freshly  drawn  blood,  in  the 
manner  already  described.     For  freshly  drawn  blood,  see 
paragraph  510,  &c.,  and  for  coagulated  blood,  see  paragraph 
524,  &c. 

The  quantitative  estimation  of  the  other  ingredients 
may  also,  if  necessary,  be  conducted  in  the  same  manner 
as  in  healthy  blood  (503,  &c.). 

SECTION  V. 
Blood  containing  an  Excess  of  Fatty  Matter. 

591.  The   average   amount   of  fat   in   healthy  blood 
appears  to  be  something  more  than  two  parts  in  a  thou- 
sand.    The  whole  of  the  oily  fat  probably  exists  in  com- 
bination with  potash  or  soda,  forming  a  kind  of  soap;  so 
that  in  the  healthy  fluid  no  oil  globules  can  be  detected. 

592.  In  certain  pathological  conditions,  we  occasionally 
meet  with  blood  containing  a  considerable  quantity  of 
free  fat,  which  is  held  in  suspension,  in  the  form  of 
minute  globules,  in  the  serum,  giving  that  fluid  a  more 
or  less  opaque  or  milky  appear- 
ance.     In    this    form    of    blood,  Fig-  67. 
which,  from  its   peculiar  appear- 

ance,  has  been  called  milky  blood, 
may  be  seen,  with  the  help  of  the. 
microscope,  innumerable  fat  glo- 
bules, which  may  be  readily  dis- 
tinguished by  their  bright  centres, 
and  black,  well-defined  outlines 


(Fig.  67).     They  may  be  separated  Fat  in  B,ood. 

by  agitating  the  serum  with  a  little 
ether,  which  will  readily  dissolve  them. 


216  MORBID    BLOOD. 

593.  The  amount  of  fat  in  any  specimen  of  blood  may 
be  determined  by  evaporating  to  dryness  a  known  weight 
of  the  fluid,  pounding  the  dry  residue,  and  boiling  it  with 
successive  small  quantities  of  ether  (545).     The  ethereal 
solution  of  the  fat  thus  obtained  is  evaporated  to  dryness 
in    a   counterpoised   capsule,   and  weighed ;   its  weight 
representing  the  proportion  of  fat  in  the  quantity  of  blood 
employed. 

594.  The  quantitative  determination  of  the  other  con- 
stituents of  the  blood  may,  if  required,  be  effected  in  the 
same  manner  as  in  the  healthy  fluid  (503,  &c.). 

SECTION  VI. 
Blood  containing  an  Excess  of  Cholesterin. 

595.  Minute  traces  of  cholesterin  appear  to  be  always 
present  in  healthy  blood,  though  some  observers  have 
failed  in  their  endeavors  to  detect  it.     The  amount,  how- 
ever, in  certain  forms  of  disease  not  unfrequently  rises 
as  high  as  015  to  0*20  in  1000  parts;  and  in  one  case  of 
so-called  milky  Hood,  Lecanu  found  not  less  than  T08  in 
1000. 

596.  When  an  excess  of  cholesterin  is  suspected  to  be 
present  in  any  specimen  of  blood,  it  may  be  separated 
and  estimated  with  tolerable  accuracy  in  the  following 
manner.     A  known  weight  of  the  blood  is  evaporated  to 

dryness  on  a  water-bath, 
Fig.  68.  and  the  dry  residue,  after 

being  reduced  to  fine 
powder  in  a  mortar,  is 
digested  for  a  few  hours 
in  ether,  the  solvent  ac- 
tion being  assisted  by 
occasional  boiling  (545). 
In  this  way  the  choles- 
terin, together  with  the 

Cholesterin.  °ther  fattV  Batters   is  dis- 

solved,  and  may  be  ob- 
tained by  evaporating  the  ethereal  solution  on  a  water- 
bath.  The  residue  is  then  deprived  of  the  oily  portion 
of  the  fat,  by  digestion  with  cold  alcohol,  which  leaves 


MORBID    BLOOD.  217 

undissolved  the  cholesterin,  with  the  other  solid  fatty 
matters ;  the  crystalline  scales  of  cholesterin  (Fig.  68), 
which  are  easily  distinguishable  from  the  rest,  may  then 
be,  for  the  most  part,  mechanically  separated  with  the 
point  of  a  knife.  Their  weight  may  then,  after  drying, 
be  ascertained  if  necessary. 

597.  The  quantitative  estimation  of  the  other  constitu- 
ents may  be  conducted  as  in  the  case  of  healthy  blood 
(503,  &c.). 

SECTION  VII. 
Blood  containing  an  Excess  of  Urea. 

598.  Minute  traces  of  urea  are  probably  always  present 
in  healthy  blood  (484),  though  the  amount  is  so  small  as 
to   be   incapable  of  determination,   unless   considerable 
quantities  of  blood  are  used.     In  some  forms  of  disease, 
however,  especially   in    Bright's   disease,  cholera,*   and 
certain  other  pathological  conditions,  in  which  the  func- 
tions of  the   urinary  organs  are  to  any  serious  extent 
interfered  with,  the  amount  of  urea  is  found  to  increase 
considerably,  and  may  frequently  be  met  with  in  a  suffi- 
ciently large  quantity  to  be  weighed. 

599.  The  detection  and  estimation  of  urea  in  the  blood 
may  be  conducted  in  the  following  manner.     A  known 
weight  of  serum  is  first  evaporated  to  dry  ness  on  a  water- 
bath,  at  a  very  gentle  heat,  a  precaution  necessary  to  be 
observed,  since  a  temperature  of  212°,  long  continued, 
such  as  is  required  in  this  analysis,  would  probably  cause 
the  decomposition  of  some  portion  of  the  urea.     The  dry 
residue  is  reduced  to  fine  powder  in  a  mortar,  and  treated 
with  distilled  water,  heated  to  about  200°,  the  quantity 
of  which  may  be  about  double  the  volume  of  the  serum 
employed  in  the  experiment.     The  mixture  is  allowed  to 
digest  for  about  half  an  hour  at  200°,  after  which  it  may 
be  filtered  from  the  insoluble  residue  of  albumen,t  which 

*  It  has  been  stated  that,  in  cholera,  a  peculiar  ferment  is  present 
in  the  blood,  which  very  rapidly  converts  the  urea  into  carbonate  of 
ammonia  (11). 

f  A  more  delicate  process  consists  in  drying  the  serum  in  vacua 
over  sulphuric  acid,  and  extracting  the  powdered  residue  with  alcohol, 
which  dissolves  the  urea. 

19 


218  MORBID    BLOOD. 

latter  must  be  washed  while  on  the  filter  with  a  little 
more  warm  water.  The  filtered  aqueous  solution  is  now 
evaporated  to  dryness,  and  the  residue  digested  with  a 
little  absolute  alcohol,  at  a  very  gentle  heat,  which  may 
be  continued  for  about  half  an  hour  ;  a  little  fresh  alcohol 
being  added  occasionally,  to  replace  that  lost  by  evapora- 
tion. The  mixture  is  then  filtered  ;  the  clear  alcoholic 
solution  is  evaporated  to  dryness,  and  the  residue  treated 
with  a  little  lukewarm  distilled  water,  which  will  then 
contain  merely  the  urea,  together  with  a  small  quantity 
of  extractive  matter. 

600.  The  aqueous  solution  thus  obtained  is  evaporated 
at  a  very  gentle  heat,  to  the  consistence  of  a  syrup,  and 
then  mixed  with  a  few  drops  of  pure  and  colorless  nitric 
acid  (16,  181),  the  mixture  being  kept  cool  by  immersing 
the  glass  containing  it  in  a   little  cold   water,  or,  still 
better,  in  a  freezing  mixture  composed  of  equal  weights 
of  crystallized  nitrate  of  ammonia  and  water.     If  urea  is 
present,  delicate  crystalline   plates   of    nitrate   of    urea 
(C?H4N2O2,HO,N05);  will  gradually  appear  (Fig.  2),  which 
if  in  sufficient  quantity,  may  be  dried  by  gentle  pressure 
between  folds  of  filtering  paper,    and   weighed.     From 
the  weight  thus  obtained,  that  of  the  urea  in  the  quantity 
of  serum  employed  may  be  calculated  as  follows : — 

Atomic  wt.  of  nitrate        Atomic  wt.        Wt.  of  nitrate         Wt.  of  urea  in  quantity  of 
of  urea.  of  urea.  obtained.  serum  employed. 

123  :        60        :  :  a  :  x 

601.  If  no  appearance  of  crystallization  can  be  detected 
with  the  naked  eye,  a  drop  of  the  acid  liquid,  cooled  by 
means  of  a  freezing  mixture,  is  to  be  examined  under 
the  microscope,  by  which  means  very  small  traces  of  urea 
may  be  detected  (181). 

602.  The  quantitative  determination  of  the  other  con- 
stituents may  be  effected  with  a  fresh  portion  of  the  blood, 
in  the  same  manner  as  in  the  healthy  fluid  (503,  &c.). 


MORBID    BLOOD.  219 


SECTION    VIII. 

Blood  containing  an  Excess  or  Deficiency  of  Inorganic  Saline 

Matter. 

603.  The  average  proportion  of  inorganic  saline  matter 
in  healthy  blood,  appears  to  be  about  seven  parts  in  1000. 
In  scurvy,  and  some  other  pathological  conditions,  their 
amount  has  been  found  to  increase,  and  has  been  known 
to  amount  to  as  much  as  eleven  parts  in  1000.     In  some 
other  diseases,  on  the  contrary,  the  amount  falls  below  the 
healthy  average. 

The  proportion  of  fixed  saline  matter  in  any  specimen 
of  morbid  blood,  may  be  determined  as  in  the  case  of  the 
healthy  fluid — viz.,  by  evaporating  to  dryness  a  known 
weight,  and  incinerating  the  residue  until  the  ash  becomes 
nearly  colorless.  The  weight  of  the  ash  thus  obtained 
represents  the  amount  of  salts  in  the  quantity  of  blood 
employed.* 

604.  The  presence  of  uric  acid  (urate  of  soda)  in  the 
blood  of  gouty  patients,  may  be  shown  by  evaporating  a 
little  of  the  fluid  to  dryness  on  a  water-bath,  and,  after 
washing  the  dry  residue  with  alcohol,  adding  a  slight 
excess  of  dilute  hydrochloric  or  acetic  acid  to  a  strong 
aqueous  solution  of  the  extract  which  proved  insoluble 
in   the  alcohol.      After  standing  a  day  or  two,  minute 
crystals  of  uric  acid,  similar  to  those  formed  in  the  urine, 
are  gradually  deposited,  and  may  be  identified  under  the 
microscope  (186,  194),  or  by  their  behavior  when  treated 
with  nitric  acid  and  ammonia  (23).     Even  in  healthy 
blood,   minute   traces   of   uric   acid  may   generally   be 
detected. 

A  simpler  test  devised  by  Dr.  Garrod,  consists  in  treat- 
ing the  serum  with  acetic  acid  in  a  watch-glass  in  which 
a  fine  thread  is  placed.  After  an  hour  or  two,  the  thread 
is  examined  by  the  microscope,  when  crystals  of  uric  acid 
are  discernible  upon  it. 

*  See  note  to  paragraph  63. 


220  MORBID    BLOOD. 

CLASS  II. — Morbid  Blood  containing  some  Abnormal  Ingredient. 


SECTION  IX. 
Blood  containing  Sugar  (O^H^O^. 

605.  The  blood  of  patients  suffering   from   diabetes, 
appears  most  commonly  to  contain  a  very  sensible  amount 
of  sugar.*  This  may  usually  be  detected  in  the  following 
manner: — 

606.  The  portion  of  serum  intended  for  examination 
is  first  evaporated  to  dryness,  either  in  vacuo  over  sul- 
phuric acid,  or  at  a  very  gentle  heat  on  a  water-bath. 
The  dry  residue  is  then  reduced  to  tolerably  fine  powder, 
and  treated  with  a  small  quantity  of  boiling  water,  which 
will  have  the  effect   of   coagulating   the  albumen,   and 
dissolving  out  the  sugar,  together  with   the  extractive 
matters  and  soluble  salts.     The  mixture  is  then  filtered, 
and  the  clear  liquid  examined  for  sugar,  by  means  of 
Trommer's  test,  which  may  be  thus  applied : — 

607.  The  liquid  is  treated  with  a  drop  or  two  of  a 
solution  of  sulphate  of  copper,  and  then  supersaturated 
with  potash  (123),  the  excess  of  which  will  probably,  if 
sugar  is  present,  redissolve  the  blue  precipitate  of  hydrated 
oxide  of  copper  at  first  thrown  down.     The  mixture  may 
now  be  gently  boiled  for  a  few  minutes,  when,  if  sugar 
is  present,  an  orange-brown  or  ochre-colored  precipitate 
of  suboxide  of  copper  will  be  thrown  down  ;   while,  if 
no  sugar  is  contained  in  the  mixture,  the  precipitate  will 
be  nearly  black  (124). 

608.  It  is  always  more  satisfactory,  when  practicable, 
even  when  Trommer's  test  affords  tolerably  decided  indi- 
cations of  sugar,  to  confirm  the  result  by  applying  also 
Bottger's  test   (127),    the   fermentation    test   (128),  and 
examining  under  the  microscope  for  the  torula  (132); 
since  certain  other  organic  matters  besides  sugar  give  rise 
to  the  formation  of  the  suboxide. 

609.  When,  after  having  proved  the  presence  of  sugar 

*  See  note  to  paragraph  484. 


MORBID    BLOOD.  221 

in  the  blood,  it  is  required  to  determine  its  amount,  the 
following  method  of  insulating  it  is,  perhaps,  the  best, 
though  the  results  must  not  be  regarded  as  by  any  means 
exact,  but  merely  as  an  approximation  to  the  truth.  The 
fermentation  process  (128)  cannot  be  here  applied,  since 
traces  of  carbonic  acid  may  be  evolved  by  some  of  the 
other  constituents  of  the  blood,  when  no  sugar  is  present. 

610.  A   known    weight   of    serum    is   evaporated   to 
dry  ness,  either  in  vacuo  over  sulphuric  acid,  or  at  a  very 
gentle  heat  on  a  water-bath.     The  dry  residue  is  then 
finely   comminuted   and  treated    with  boiling  water,  in 
which  it  may  be 'allowed  to  digest  for  three  or  four  hours, 
in  order  to  insure  the  solution  of  the  whole  of  the  soluble 
matter.      The  aqueous  solution  is   separated    from   the 
albumen   by    filtration,  and   evaporated   to   dryness  as 
before.     The  dry  residue  is  now  digested  with  alcohol, 
which    leaves  undissolved    portions  of  the   saline   and 
extractive  matters.     The  alcoholic  solution  is  mixed  with 
a  little  alcoholic  solution  of  potash,   and  set  aside  for 
twenty-four  hours,  when  a  crystalline  compound  of  sugar 
and  potash  will  be  deposited.  The  alcoholic  solution  may 
now  be  poured  or  filtered  off,  and  the  crystalline  com- 
pound dissolved  in  water  with  a  view  to  the  determina- 
tion of  the  quantity  of  sugar  by  means  of  the  standard 
alkaline  solution  of  copper  (352)- 

When  the  freshly  drawn  blood  can  be  obtained,  the 
following  process  recommended  by  Figuier  may  be 
adopted.  About  six  ounces  of  blood  are  defibrinated  by 
stirring  (477),  and  mixed  with  three  volumes  of  a  satu- 
rated solution  of  sulphate  of  soda.  The  blood  globules 
are  then  filtered  off,  and  the  filtrate  mixed  with  two 
volumes  of  alcohol,  to  coagulate  the  albumen  and  pre- 
cipitate the  sulphate  of  soda.  These  having  been  filtered 
off,  the  solution  is  evaporated  to  dryness  on  the  water- 
bath,  the  residue  extracted  with  water,  and  the  sugar 
determined  by  the  alkaline  copper-solution  (352). 

611.  The  quantitative  determination  of  the  other  con- 
stituents of  blood  containing  sugar  may  be  effected  in 
the  same  manner  as  in  the  case  of  healthy  blood,  the 
weight  of  the  sugar  being  deducted  from  the  extractive 
matter  (503,  &c.). 

19* 


222  MOKBID    BLOOD. 

SECTION  X. 
Blood  containing  Biliary  Matter. 

612.  In  jaundice,  and  some  other  affections  in  which 
the  functions  of  the  liver  are  interfered  with,  an  accu- 
mulation of  biliary  matter  is  found  to  take  place  in  the 
blood,  giving  the  serum  a  more  or  less  decided  saffron 
or  orange-brown  color,  which  is  due  to  the  peculiar  color- 
ing matter  of  the  bile,  called  biliphoein  (cholepyrrhin). 

613.  The  presence  of  the  bile  in  the  blood  may  be 
detected  by  adding  to  a  little  of  the  clear  serum  a  few 
drops  of  nitric  acid,  which  will  throw  down  the  albumen ; 
the  precipitate  having,  if  biliary  matter  (biliphoein)  is  pre- 
sent, a  decided  greenish  tint,  while  in  healthy  serum  it 
would  be  white,  or  very  nearly  so. 

614.  If  so  small  a  quantity  of  bile  is  present  as  to  fail 
in  producing  a  perceptibly  green  color  with  nitric  acid, 
a  little  of  the  suspected  serum  may  be  first  concentrated 
by  evaporation  at  a  temperature  not  exceeding  120°  or 
130°,  and  then  exhausted  with  alcohol  or  water,  and  the 
solution  tested  in  the  manner  already  described  in  the 
case  of  urine  (149— 152). 

615.  We  have  at  present  no  means  of  estimating  the 
quantity  of  biliary  matter  contained  in  blood,  though  the 
depth  of  color  of  the  serum  furnishes  some  indication  of 
the  relative  amount  present.     The   quantitative  deter- 
mination of  the  other  constituents  of  the  blood  may  be 
made  in  the  same  manner  as  in  the  analysis  of  the  healthy 
fluid  (503,  &c.). 

SECTION  XI. 
Blood  containing  Pus. 

616.  The  existence  of  pus  in  morbid  blood  is  probably 
by  no  means  a  rare  occurrence,  especially  in  diseases 
which   are   attended  with   suppuration.     Its   detection, 
however,  is  far  from  easy,  since  we  possess  no  character- 
istic chemical  test  by  which  it  may  be  distinguished  from 
the  ordinary  constituents  of  the  blood;  and  in  micro- 
scopic appearance,  the  pus  granules  very  closely  resemble 
the  colorless  corpuscles  which  are  always  present  in  the 
blood  (464).    The  pus  granules  are  in  general  somewhat 
larger  than  the  white  corpuscles  of  the  blood,  and  when 


MORBID    BLOOD.  223 

treated  with  dilute  acetic  acid,  develop  internal  nuclei, 
which  are  usually  from  three  to  five  in  number,  and  more 
distinct  than  those  in  the  white  corpuscles  of  the  blood. 
The  pus  granules,  when  present  in  blood,  appear  to  have 
a  tendency  to  adhere  together  in  groups  of  five  or  six ; 
while  the  colorless  corpuscles  of  the  blood  always  float 
detached  from  each  other. 

617.  According  to  Heller,  the  granules  oL  pus,  when 
mixed  with  blood,  subside  much  more  slowly  than  the 
blood-corpuscles;  so  that  when  present,  they  may  always 
be  found  in  the  uppermost  layer  of  the  coagulum.*     He 
recommends  a  thin  slice  to  be  taken  from  the  upper  sur- 
face of  the  latter,  which,  after  being  mixed  with  a  little 
distilled  water,  should  be  filtered  through  muslin,  in  order 
to  separate  the  fibrin.     The  blood-corpuscles  are  for  the 
most  part  dissolved  by  the  action  of  the  water  (458);  and 
after  allowing  the  filtered  liquid  to  stand  a  short  time  in 
a  tall  glass,  the  pus  granules  will  be  found  at  the  bottom 
of  the  liquid,  and  may  be  detected  under  the  microscope. 

618.  The  action  of  ammonia  upon  pus  has  been  pro- 
posed by  Donne*  as  a  test  for  its  presence  in  the  blood. 
When  blood,  free  from  pus,  is  mixed  with  ammonia,  it 
becomes  clear ;  while  if  pus  is  present  in  any  conside- 
rable quantity,  the  liquid  becomes  more  or  less  gelatinous. 
If  the  amount  of  pus  present  is  small,  stringy  flocculi  only 
are  formed,  which  subside  to  the  bottom  of  the  liquid. 

SECTION  XII. 
Blood  containing  Animalcules. 

619.  Instances   have   occasionally  been  observed,  in 
which  minute  thread-like  animalcules  have  been  present 
in  considerable  numbers  in  the  blood.     Those  described 
by  Dr.  Goodfellow,  which  he  detected  in  the  blood  of  a  pa- 
tient suffering  from  fever,  measured  from  -5^30^ to  3uWta 
of  an  inch  in  length,  and  from  7aJoutQ  to  2^¥tfta  °f 
an  inch  in  diameter.    The  only  method  of  detecting  such 
entozoa  in  the  blood,  is  to  examine  it  carefully  under  the 
microscope,  with  as   high  a  magnifying  power  as  the 
observer  has  at  his  command. 

*  This  remark  also  applies  to  the  colorless  corpuscles. 


PART    IV. 

MILK,  BILE,  MUCUS,  PUS,  BONE,  &c. 


CHAPTER    I. 

MILK. 

SECTION  I. 
General  Characters  of  Milk. 

620.  Milk,  as  is  well  known,  is  a  watery  liquid,  having 
in  solution  a  certain  amount  of  casein,  sugar  of  milk,  or 
lactine  and  extractive  matter,  together  with  several  inor- 
ganic salts,  and  holding  in  suspension  myriads  of  ex- 
tremely minute  globules  of  fatty  matter,  plainly  visible 
through  the  microscope,  which  give  the  fluid  its  peculiar 
white  and  opaque  'appearance.     It  has  a  pleasant  and 
rather  sweetish  taste,  and  a  slight  agreeable  smell,  espe- 
cially while  warm.     The  specific  gravity  of  milk  varies 
considerably ;  that  of  woman  being  sometimes  as  low  as 
1020  (the  average  being  1032),  while  that  of  the  sheep 
is  as  high  as  1041. 

621.  Fresh  milk  is  almost  invariably  slightly  alkaline 
to  test  paper,  but  on  exposure  to  the  air,  especially  in 
warm  weather,  it  rapidly  becomes  acid,  owing  to  the  con- 
version of  the  sugar  of  milk  into  lactic  acid  (2J5"0,  C"12 
H100W\  under  the  influence  of  the  casein,  which  acts  as 
a  ferment  (630).     If  the  milk  has  been  long  retained  in 
the   mammary  glands,    this  change   occasionally  takes 
place  before  being  drawn;  and  in  some  morbid  condi- 
tions also,  the  milk  is  found  to  have  an  acid  reaction 
even  when  freshly  drawn. 


MILK.  225 

622.  When  allowed  to  stand  for  a  few  hours,  the  fatty 
globules,  which  have  a  somewhat  lower  specific  gravity 
than  the  fluid  portion  of  the  milk,  gradually  rise  to  the 
surface,  carrying  with  them  a  portion  of  the  caseous  mat- 
ter, forming  a  layer  of  cream,  which  is  more  or  less  thick 
and  copious  in  proportion  to  the  richness  of  the  milk.* 

623.  If  a  little  acetic  or  lactic  acid,  rennet,  or  even 
sour  milk,  be  added  to  hot  milk,  the  casein  of  the  latter 
is   precipitated  in  the  coagulated  form;    and   the  same 
effect  is  produced  by  warming  milk  or  cream  which  has 
been  allowed  to  turn  sour ;  the  sourness  being  due  to  the 
lactic  acid,  into  which  the  sugar  of  milk  has  been  con- 
verted.    The  solid  and  liquid  portions  into  which  the 
milk  is  thus  divided,  are  commonly  called  curds  and 
whey. 

624.  Before  describing  the  mode  of  analyzing  milk,  I 
will  briefly  notice  the  several  constituents  which  we  find 
contained  in  it — viz.,  casein,  sugar  of  milk,  fat  globules, 
and  saline  matter. 

SECTION  II. 
Casein. 

625.  Casein  is  one  of  the  so-called  protein- compoundsf 
(472)  peculiar   to  the  milk,  and    constitutes   the    chief 
source  of  nourishment  to  the  young  animal;   for  which 
purpose  it  is  admirably  adapted,  from  the  readiness  with 
which  it  appears  capable  of  being  converted  into  the 
other  bodies  of  the  same  class — viz.,  fibrin  and  albumen. 

626.  It  may  be  obtained  in  a  state  of  tolerable  purity 
by  evaporating  a  quantity  of  milk  to  dryness  on  a  water- 
bath,  and  boiling  the  dry  residue  in  successive  portions 
of  ether,  in  order  to  dissolve  out  the  fat.     The  residue 
which  remains  insoluble  in  the  ether  is  then  dried,  and 
digested  in  water,  which  will  dissolve   the   casein  and 

*  According  to  Miiller,  fresh  milk,  when  allowed  to  stand,  first 
undergoes  a  peculiar  change,  resulting  in  the  dissolution  of  the  mem- 
branes inclosing  the  fat  globules,  so  that  the  proportion  of  fat  which 
can  be  extracted  by  ether  continues  to  increase  for  some  time  after  the 
milk  has  been  drawn. 

t  See  note  to  471. 


226  MILK. 

other  soluble  matters  of  the  milk.  On  adding  alcohol  to 
the  aqueous  solution,  a  great  part  of  the  milk-sugar  is 
thrown  down  in  the  form  of  a  precipitate,  leaving  the 
casein  in  solution  together  with  some  milk-sugar  and 
soluble  salts. 

It  may  be  obtained  in  a  purer  condition  by  adding  a 
little  hydrochloric  acid  to  skimmed  milk,  collecting  the 
curd  upon  a  linen  strainer,  and  washing  it  first  with 
water,  then  with  water  slightly  acidified  with  hydrochlo- 
ric acid,  and  finally  with  pure  water.  If  it  be  then 
heated  to  110°  with  a  large  volume  of  water,  the  greater 
portion  will  dissolve  slowly,  and  may  be  reprecipitated 
from  the  filtered  solution  by  neutralization  with  carbo- 
nate of  ammonia.  After  washing  with  water,  and  warm- 
ing, first  with  alcohol,  and  afterwards  with  ether  to  re- 
move all  fatty  matter,  the  casein  is  as  pure  as  it  can  be 
obtained.  It  always  leaves  an  ash  of  phosphate  of  lime 
when  burnt. 

627.  It  is  most  probable  that  pure  casein  is  insoluble, 
or  very  sparingly  soluble,  in  water,  and  owes  its  solu- 
bility in  milk  to  the  small  quantity  of  alkali  which  is 
present.     When   dry,   it   closely   resembles   fibrin   and 
albumen  in  appearance  (479),  and  its  behavior  with  rea- 
gents is  in  most  cases  very  similar ;  it  differs  from  the 
latter  chiefly  in  not  coagulating  when  heated ;  and  it  is 
precipitated  by  acetic,  and  nearly  all  the  acids,  but  redis- 
solves  in  a  considerable  excess  of  most  of  them.     Its 
solution  in  acetic  acid  is  precipitated  by  dilute  sulphuric 
acid.     The«ferrocyanide  and  ferridcyanide  of  potassium 
also  cause  precipitates  in  solutions  of  casein. 

SECTION  III. 
Sugar  of  Milk  or  Lactine  (C34H24034). 

628.  The  sugar  contained  in  milk  may  be  prepared  in 
the  following  manner:     The  curd,  including  the  greater 
part  of  the  casein  and  fat  globules,  is  first  separated  by 
the  addition  of  a  few  drops  of  acid  to  hot  milk,  and  the 
remaining  traces  of  those  substances  are  then  removed 
by  mixing  a  little  well-beaten  white-of-egg  with  the  whey 
when  cold,  and  afterwards  boiling  the  mixture.     The 


MILK.  227 

whey  thus  clarified  by  the  coagulating  albumen  of  tho 
egg,  is  filtered  from  the  precipitate  by  passing  it  through 
muslin  or  calico;  and  the  clear  liquid  may  then  be 
evaporated  to  about  one-fourth  or  one-fifth  its  bulk,  and 
set  aside  in  a  cool  place  for  a  few  days.  The  sugar  will 
gradually  separate  from  the  liquid,  in  the  form  of  minute 
hard  crystals,  which  adhere  to  the  surface  of  the  contain- 
ing vessel.  These  may  be  purified  by  dissolving  them 
again  in  water,  -boiling  the  solution  with  animal  charcoal, 
and  recry  stall  i  zing. 

629.  This  variety  of  sugar  is  less  sweet  than  that  ob- 
tained either  from  the  cane  or  the  grape  (114)  ;  it  is  also 
harder,  and  less  soluble  in  water,  requiring  as  much  as 
five  or  six  times  its  weight  of  cold,  and  two  and  a  half 
times  its  weight  of  hot,    water  to  dissolve  it.     When 
mixed  with  a  little  hydrochloric  or  sulphuric  acid,  sugar 
of  milk  gradually  becomes  converted  into  grape  sugar 
(C12H14014),  and  this  change  takes  place  more  rapidly  if 
the  solution  is  boiled. 

630.  Under  the  influence  of  the  caseous  matter  of  the 
milk,  this  form  of  sugar  gradually  passes  into  lactic  acid 
(2HO,(712/710010),  a  change  easily  accounted  for,  since  the 
formula  of  the  sugar  is  a  multiple  of  that  of  the  acid,  one 
equivalent  of  the  former  being  broken  up  into  two  of  the 
latter. 


SECTION  IV. 
Fat   Globules. 

631.  The  minute  globules  which  are  held  suspended 
in  milk,  and  to  which  the  opacity 
arid  whiteness  of  the  fluid  are  due,  Fis-  69. 

consist  mainly  of  oily  fat,  which 
appears  to  be  surrounded  by  a  thin 
covering  of  insoluble  matter  differ- 
ing  in  its  properties  from  fat,  and 
probably  composed  of  one  of  the 
protein  compounds.  It  is  for  this 
reason  that  the  fat  globules  cannot 
be  removed  from  milk  by  agitation  Milk 

with  ether,  unless  potash  be  pre- 
viously added  to  dissolve  the  membranous  envelopes. 


228 


MILK. 


colostrum  corpuscles. 


632.  The  size  of  the  globules  in  healthy  milk  varies 
from  a  mere  point  to  about  27To^th 
Fig.  70.  of  an  inch  in  diameter,  the  aver- 

age size  being  rather  more  than 
^th  (Fig.  69). 

633.  In  the  milk  which  is 
secreted  during  the  first  few  days 
of  lactation,  called  the  colostrum, 
and  which  is  always  much  richer 
in  quality  than  ordinary  milk, 
we  find  in  addition  to  the  com- 
mon milk  globules,  numerous 
granular  corpuscles  of  a  pale 
yellowish  color,  and  considerably 
larger  than  the  others,-  their  diameter  varying  from 
sflVffth  to  s^th  of  an  inch  (Fig.  70).  Similar  corpuscles 
are  also  occasionally  present  in  milk  secreted  during 
disease.  They  appear  to  be  almost  peculiar  to  human 
milk,  being  rarely  met  with  in  that  of  the  cow  and  other 
animals. 

634.  The  fatty  matter  of  milk  consists  for  the  most 
part  of  a  solid  fat,  called  margarine  (C108H]04O12),  mixed 
with  a  liquid  fat  or  oil,  called  oleine  (C114H104O12),  together 
with  small  quantities  of  butyrine  and  other  fats.  The 
proportion  in  which  these  several  fats  are  found  mixed 
in  milk,  varies  considerably,  being  influenced  by  the 
health  and  food  of  the  individual,  the  season  of  the  year, 
and  other  circumstances.  A  specimen  of  the  fat  con- 
tained in  cow's  milk,  analyzed  by  Bromeis,  contained  — 


Margarine  .... 
Oleine  ..... 
Butyric,  caproic,  and  capric  acids 


30 

2 

100* 


*  Heintz  pronounces  the  margarine  of  butter  to  be  a  mixture  of 
stearine  (CIUHU0012)  and  palmitine  (C^H^O^).  He  has  also  ob- 
tained a  new  acid  called  butic  or  butinic  acid  (HO,C40H3903)  from  butter, 
as  well  as  eaprylic  (HO,CI6HI5O3)  and  myristic  (HO,C28H2703)  acids. 


MILK.  229 

SECTION  V. 
Saline  Matters. 

635.  It  is  probable  that  the  following  salts  are  present 
in  milk,  though  an  analysis  of  the  ash  will  not,  of  course, 
detect  the  organic  and  volatile  compounds  included  in 
the  list,  since  they  are  either  decomposed  or  volatilized 
during  the   process   of   incineration:   the   chlorides   of 
potassium  and  sodium ;  the  phosphates  of  potash,  soda, 
lime,  and  magnesia,  with  traces  of  phosphate  'of  the  per- 
oxide of  iron. 

636.  According  to  Haidlen,  the  ash  obtained  by  in- 
cinerating 1000  parts  of  cow's  milk,  consisted,  in  two 
instances,  of  the  following  substances : — 

i.  ii. 

Phosphate  of  lime        .  2-31  3-44 


Phosphate  of  magnesia 
Phosphate  of  peroxide  of  iron 
Chloride  of  potassium  . 
Chloride  of  sodium 
Soda 


0-42  0-64 

0-07  0-07 

1-44  1-83 

0-24  0-34 

0-42  0-45 

4-90  6-77 


637.  The  presence  of  these  several  salts  may  be  proved 
by  applying  to  a  solution  of  the  ash  in  water  and  hydro- 
chloric acid,  the  tests  mentioned  in  the  chapters  on  the 
urine  and  the  blood  (41,  490,  &c.). 

SECTION  VI. 
Composition  of  Human  Milk. 

638.  In  healthy  human  milk,  the  several  constituents 
which  I  have  now  briefly  described,  are  not  always  pre- 
sent in  the  same  relative  proportions;  various  circum- 
stances, as  those  of  age,  temperament,  and  food  of  the 
mother,  as  well  as  the  period  of  lactation,  causing  con- 
siderable variation  in  the  composition  of  the  secretion. 
The  following  examples  will  serve  to  show  to  what  extent 
these   variations    usually   occur.     The    proportions   are 
calculated  in  1000  parts  of  milk. 

20 


230 


MILK. 


Analysis  I.     (Simon.) 

Showing  the  Mean  of  Fourteen  Analyses  made  at  different  periods^  with 
the  Milk  of  the  same  Woman. 

Water 883-6 

Solid  constituents 116-4 

Butter* 25-3 

Casein 34-3 

Sugar  of  milk  and  extractive  matters     .         .         .  48-2 

Fixed  salts 2-3 


Analyses  II,  III,  and  IV.     (Clemm.) 


The  fourth  day 
after  delivery. 

879-848 
120-152 
42-968 
35-333 


Water 

Solid  constituents 
Butter     . 
Casein    . 
Sugar    of     milk ") 

and  extractive  >   41-135 
matters        .      J 
Salts       .         .  2-095 


The  ninth  day 
after  delivery. 

885-818 

114-182 

35-316 

36-912 

42-979 
1-691 


The  twelfth  day 
after  delivery. 

905-809 
94-191 
33-454 
29-111 

31-537 


Analysis  VII.     (Chevallier  and  Henri.) 


Water 

Solid  constituents 

Butter     . 

Casein    . 

Sugar  of  milk 

Salts 


1-939 


879-8 

120-2 

35-5 

15-2 

65-0 

4-5 


The  recent  analyses  of  MM.  Vernois  and  Alfred  Bec- 
querel  give  the  following  as  the  composition  of  normal 
human  milk: — 


Water 
Sugar 

Casein  and  extractive 
Butter     . 
Salts  (ash)      . 


.  889-08 
.  43-64 
.  39-24 
.  26-66 
.  1-38 

1000-00 


Specific  gravity,  1032-67. 


*  The  portion  of  milk  drawn  at  the  commencement  of  a  draught 
(whether  from  a  woman  or  a  cow)  is  not  so  rich  in  butter  as  that 
drawn  at  the  conclusion. 


MILK.  231 

SECTION  VII. 
Composition  of  the  Milk  of  other  Animals. 

639.  The  proportion  of  the  several  constituents  is 
found  to  differ  considerably  in  the  milk  of  different 
animals.*  The  subjoined  table,  showing  the  composition 
of  the  milk  of  a  few  of  the  more  important  domestic 
animals,  from  the  analyses  of  Chevallier  and  Henri,  will 
serve  to  illustrate  this : — 

Cow.  Ass.  Goat.  Ewe. 

Casein  4-48  1-82  4-08  4-50 


Butter 

Sugar  of  milk 
Saline  matter 
Water 


3-13  0-11  3-32  4-20 

4-77  6-08  5-28  5-00 

0-60  0-34  0-52  0-68 

87-02  91-65  86-80  85-02 

100-00  100-00  100-00  100-00 


639  a.  According  to  the  analysis  of  Morin,f  milk  con- 
tains a  considerable  quantity  of  a  substance  resembling 
gelatine,  which  he  proposes  to  call  galactine.  Both  this 
substance  and  the  caseine  of  milk  possess  a  specific 
power  of  emulsifying  the  fats,  and  he  thus  accounts  for 
the  minute  state  of  division  of  the  fatty  matter  in  milk. 
It  is  also  asserted  that  the  coagulum  obtained  by  boiling 
milk  which  has  been  curdled  by  acetic  acid  and  filtered, 
consists  of  albumen.  The  results  of  Morin's  analysis  of 
cow's  milk  were : — 


Casein         .... 
Soda  in  combination  with  it 
Butter         .... 

36-14 
0-48 
13-78 
3-90 

Sugar  of  milk 
Galactine  (gelatigenous  matter) 

36-00 
3-82 
.       5-42 

Phosphate  of  lime 2-56 

Chloride  of  sodium 0-56 

Water 897-34 

1000-00 


*  Schlossherger  describes  the  milk  of  the  carnivora  as  having 
usually  an  acid  reaction.  The  milk  of  stall-fed  cows,  mares,  and  ewes 
kept  on  green  food  is  also  said  to  be  frequently  acid. 

f  Journof  Pharm.  (3),  xxv.  71. 


232  QUANTITATIVE   ANALYSIS    OF    MILK. 


CHAPTEE  IT. 

QUANTITATIVE  ANALYSIS   OF  MILK. 

640.  Two  portions  of  milk,  one  weighing  about  100 
grains,  and  the  other  about  400  grains,  are  to  be  accurately 
weighed,  the  first  in  a  platinum  crucible  or  capsule,  and 
the  second  in  a  porcelain  capsule;  both  the  vessels  having 
been  previously  weighed   or  counterpoised.     The   first 
portion,  of  100  grains,  we  will  call  A,  and  the  second,  of 
400  grains,  we  will  call  B. 

641.  Treatment  of  the  portion  A. — This   portion,  after 
being  weighed,  is  to  be  evaporated  to  dryness  on  a  water- 
bath,  or,  still  better,  on  a  chloride-of-calcium  bath  heated 
to  about  220°,  until,  on  being  weighed  at  intervals  of 
half  an  hour  or  an  hour,  it  ceases  to  lose  any  further 
weight.     The  weight  of  the  dry  residue  will  then  repre- 
sent  the   amount   of  SOLID   MATTER   contained   in   the 
quantity  of  milk  used,  while  the  loss  of  weight  during 
evaporation  shows  the  amount  of  WATER. 

642.  In  these  and  the  other  determinations,  the  pro- 
portion present  in  1000  parts  of  the  milk  is  calculated  in 
the  following  manner : — 

{Wt.  of  milk  1         (  Wt.  of  each  )  (  Proportion   of  that  ) 

used  in  the  [•    :    -j  constituent  I    :  :  1000   -^  constituent  in  1000  [• 
experiment,  j         (.   obtained.    J  (  parts  of  the  milk.  J 

643.  The  weight  of  the  dry  residue  having  been  noted, 
the  crucible,  with  its  contents,  is  to  be  placed  over  a 
lamp,  and  kept  at  a  red  heat  until  the  whole  of  the  char- 
coal is  burnt  away,  and  the  ash  becomes  white  or  nearly 
so.     The  weight  of  the  ash  thus  obtained  will  represent 
the  amount  of  INORGANIC  SALINE  MATTER  in  the  quantity 
of  milk  evaporated ;  from  which  the  proportion  in  1000 
parts  may  be  calculated  as  before  (642).* 

*  See  foot-note  to  paragraph  63. 


QUANTITATIVE    ANALYSIS    OF    MILK.  233 

644.  Treatment  of  the  portion  B. — This  portion,  after 
being  weighed,  is  to  be  mixed  with  about  one-fourth  its 
weight  of  fine-pounded  hydrated  sulphate  of  lime  (CaO, 
S03  +  2Aq),  or  unburnt  gypsum,  with  which  it  is  to  be 
well  stirred  for  a  short  time,  and  then  raised  to  a  tem- 
perature of  212°;  by  which   means    the  whole   of  the 
casein  will  become  coagulated,  and  insoluble  in  water. 
The  mixture  is  now  to  be  evaporated  to  dry  ness  on  a 
water-bath,  being  occasionally  stirred,  in  order  that  the 
solid  residue  of  the  milk  may  be  pretty  uniformly  mixed 
with  the  sulphate  of  lirne. 

645.  The  mass,  when  dry,  is  then  easily  reduced  to 
powder;  after  which  it  is  to  be  digested  with  successive 
small  quantities  of  ether  (545),  which  will  dissolve  out 
the  whole  of  the  fatty  matter.     The  ethereal  solution  is 
now  evaporated   to  dryness  on  a  water-bath,  and  the 
residue  weighed;  its  weight  representing  the  amount  of 
FAT  in  the  quantity  of  milk  operated  on;  from  which  the 
proportion  present  in  1000  parts  of  milk  may  be  calcu- 
lated as  before  (642). 

646.  The  portion  of  the  residue  which  proved  insoluble 
in  ether  (645),  is  now  to  be  treated  with  hot,  moderately 
strong  alcohol,  as  long  as  anything  dissolves.     In  this 
way,    the   whole   of  the   sugar,   together   with   a   little 
saline  matter  and  alcohol-extractive,  is  dissolved.     The 
alcoholic  solution  is  to  be  evaporated  to  dryness  on  a 
water  or  chloride-of-calcium  bath,  and  the  dry  residue, 
having  been  accurately  weighed,  is  incinerated;  the  dif- 
ference between  the  weight  before  and  after  incineration 
will  then  represent  the  quantity  of  SUGAR,  with  a  little 
alcoholic  extractive  matter,  in  the  portion  of  milk  em- 
ployed.    The  proportion  contained  in  1000  parts  is  then 
calculated  as  in  former  cases  (642). 

The  sugar  may  be  much  more  exactly  determined  by 
means  of  the  alkaline  copper-solution,  as  described  at 
(352).  100  grs.  of  the  milk  are  acidified  with  hydro- 
chloric acid,  heated  to  coagulate  the  casein,  and  filtered  ; 
after  washing  the  coagulum  once  or  twice  with  water,  the 
filtrate  and  washings  are  boiled  in  a  flask  for  about  an 
hour,  replacing  the  water  which  evaporates,  in  order  to 
convert  the  milk-sugar  into  grape-sugar,  since  the  former 

20* 


234  MILK    DURING    DISEASE. 

does  not  reduce  the  same  proportion  of  oxide  of  copper. 
The  volume  of  the  liquid  is  then  made  up  to  1000  grs., 
and  the  determination  proceeded  with  as  in  (352). 

647.  The  proportion  of  CASEIN  may  be  estimated  by 
adding  together  the  amount  of   water,  fat,  sugar,  and 
saline  matter,  already  ascertained  as  being  present  in 
1000  parts  of  the  milk,  and  deducting  the  sum  of  them 
from  1000. 

648.  The  caseine  may  also  be  approximately  determined 
in  another  weighed  portion  of  milk  by  acidulating  with 
acetic  acid,  boiling,  collecting  the  curd  upon  a  weighed 
filter,  washing  two  or  three  times  and  drying  at  212°. 
From  its  weight  that  of  the  fatty  matter  contained  in  the 
milk  (645)  should  be  deducted. 


CHAPTER   III. 

MILK   DURING  DISEASE. 

649.  THE   milk  which  is  secreted  during  disease  is 
usually  more  or  less  modified  in  its  composition ;  even 
slight  derangements  of  the  system,  and  any  great  mental 
anxiety  or  sudden  emotion  of  fear,  &c.,  not  unfrequently 
have  the  effect  of  disturbing,  in  a  remarkable  manner, 
the  natural  character  of  the  secretion.     The  exact  nature 
of  these  changes  is  very  imperfectly  understood.     They 
are  probably  sometimes  merely  variations  in  the  relative 
proportions  of  the  several  constituents  of  the  healthy 
fluid ;  at  others,  and  perhaps  more  frequently,  certain 
abnormal  matters  are  formed. 

650.  With  the  assistance  of  the  microscope,  we  are  not 
unfrequently  able,  with  great  facility,  to  detect  the  pre- 
sence of  certain  morbid  products  which  are  not  found  in 
the  healthy  secretion.     The  peculiar  form  of  milk  called 
the  colostrum,  which  is  secreted  during  the  first  few  days 
of  lactation,  has  been  already  mentioned  as  differing  very 
considerably  in   microscopic  appearance   from    healthy 
milk,  and  as  containing  numerous  granular  corpuscles, 


MILK    DURING    DISEASE. 


235 


much  larger  than  the  ordinary  milk  globules  (633).  The 
corpuscles  of  the  colostrum  also  show 'a  tendency  to 
adhere  to  each  other,  while  the  globules  of  the  healthy 
fluid  usually  float  freely  about.  It  occasionally  happens 
that  the  milk,  instead  of  changing,  in  the  course  of  a  few 
days,  to  its  more  natural  condition,  continues  for  a  length 
of  time  to  possess  the  characters  peculiar  to  colostrum  ; 
and  has  even  been  observed  to  change  back  again  to  this 
condition,  after  being  secreted  for  a  time  in  a  healthy 
state.  The  presence  of  the  colostrum  corpuscles  (Fig. 
70),  and  the  slightly  viscid  appearance  also  characteristic 
of  this  condition,  may  at  once  be  detected  under  the 
microscope. 

651.  The  presence  of  pus,  which  during  the  formation 
of  a  mammary  abscess  often  finds  its  way  into  the  milk, 
may  also  be  detected  under  the  microscope,  by  the  occur- 
rence of  the  peculiar  pus  granules  (Fig.  71).  Blood- 
corpuscles,  too  (451),  are  also  found,  though  more  rarely 
than  those  of  pus,  owing,  in  most  cases,  to  the  rupture 
of  some  of  the  minute  bloodvessels  with  which  the 
mammary  gland  is  permeated  (Fig.  72.) 


Fig.  71. 


Fig.  72. 


*     -**»«o?*    I**   «i 


Pus  in  Milk. 


Blood  in  Milk. 


652.  Urea  is  said  to  have  been  found  in  the  milk  of 
women  affected  by  Bright's  disease.  In  addition  to  the 
strictly  morbid  products,  other  substances,  especially 
certain  salts,  which  have  been  taken  into  the  system  either 
in  the  food  or  as  medicine,  appear  occasionally  to  find 
their  way  into  the  milk,  where  they  may  sometimes  be 
detected  by  the  proper  tests. 


236  THE    ADULTERATION    OF    MILK. 

Analysis  of  the  Colostrum  of  a  Woman,  together  with  that  of  the  Healthy 
Milk  of  the  same  individual.     (Simon.) 

Colostrum.  H^ 

Water 828-0  887-6 

Solid  constituents       ....       172-0  112-4 

Fat 50-0  25-3 

Casein 40-0  34-3 

Sugar  of  milk          ....         70-0  48-2 

Saline  matter          ....           3-1  2-3 


CHAPTER  IY. 

THE   ADULTERATIONS   OF   MILK. 

653.  IT  is  well  known  that  much  of  the  milk  which  is 
supplied  in  large  towns  is  almost  constantly  more  or  less 
adulterated,  and  although  the  substances  employed  for 
the  purpose  are  in  most  cases  comparatively  innoxious, 
it  is  much  to  be  wished  that  some  simple  and  efficient 
test  of  its  genuineness  and  purity  could  be  devised,  capa- 
ble of  being  applied  by  those  who  are  unaccustomed  to 
experiment. 

654.  The  chief  mode  of  adulteration  practised  in  this 
country  consists  in  diluting  the  rnilk  with  water,  and  at 
the  same  time  occasionally   removing  the  cream.     To 
correct  the  bluish  color  of  the  impoverished  milk,  it  is 
said  that  a  little  annatto  is  sometimes  added.     Milk  has 
been  occasionally  found  adulterated  with  gum,  flour,  and 
starch  to  conceal  its  diluted  condition,  and  it  is  even 
asserted  that  the  clumsy  fraud  of  adding  chalk  and  emul- 
sion of  sheep's  brains  has  been  detected. 

655.  On  examining  a  little  of  the  milk  under  the  micro- 
scope, the  peculiar  granules  of  starch  and  flour  may  be 
readily  seen  (Fig.  73a),  larger  and  more  oval  than  the 
milk  globules  if  either  of  those  substances  is  present; 
and  when  examined  with  polarized  light,  each  granule 
will  be  found  to  exhibit  a  dark  cross,  as  shown  at  b  in 
the  figure.      Should   any  doubt  exist  as  to  their  real 
nature,  the  addition  of  a  drop  or  two  of  a  solution  of 


THE    ADULTERATION    OF    MILK.  237 

iodine  will  impart  to  the  farina  granules  a  dark  purplo 
color. 

Fig.  73. 


Starch  Granules. 

Gum  may  be  detected  by  acidulating  the  milk  with 
acetic  acid,  boiling,  filtering  off  the  coagulum,  and  mixing 
the  filtrate  with  alcohol,  when  the  gum  is  deposited  and 
may  be  recognized  by  its  behavior  with  water.  The 
presence  of  annatto  would  cause  the  milk  to  assume  a 
brown  color  on  addition  of  carbonate  of  soda. 

656.  The  microscope  will  also  serve  to  show  the  pre- 
sence of  macerated  brain,  which  may  be  recognized  by 
the  occurrence  of  fragments  of  nerve  and  other  organized 
structures,  not  found  in  pure  milk. 

657.  The  presence  of  chalk  may  be  still  more  easily 
discovered,  since,  owing  to  its  specific  weight,  it  soon 
subsides  to  the  bottom  of  the  liquid,  where  it  may  at 
once  be  recognized  by  its  effervescing  on  the  addition  of 
a  little  dilute  hydrochloric  acid. 

658.  We   have   no   chemical   means   of  ascertaining 
whether  water  has  been  fraudulently  added  to  milk,  the 
only  effect  being  to  dilute  it,  and   render  it  of  poorer 
quality,  which   might    arise   from    natural    causes.     A 
knowledge  of  the  specific  gravity  will  not  even  allow 
us  to  decide  as  to  the  richness  of  the  milk,  since  the 
abstraction  of  a  portion  of  the  cream,  which  has  a  lower 
specific  gravity  than  milk,  may  be  made  to  neutralize 
the  effect  produced  by  the  addition  of  water;  the  ten- 
dency of  the  removal  of  the  cream  being  to  raise  the 
specific  gravity  of  the  fluid,  and  that  of  the  addition  of 
water,  to  lower  it.    A  specimen  of  milk,  therefore,  which 
has  been  impoverished  by  the  abstraction  of  its  cream, 


238  THE    ADULTEKATION    OF    MILK. 

and  still  further  weakened  by  the  addition  of  water,  may 
be  made  to  possess  the  same  specific  gravity  as  it  had 
when  taken  pure  from  the  udder. 

For  most  practical  purposes  it  is  sufficient  to  compare 
the  relative  volumes  of  cream  furnished  by  equal  quan- 
tities of  different  specimens  of  milk.  This  may  be  readily 
effected  by  allowing  the  milk  to  stand  in  a  graduated 
tube  (lactometer)  for  twenty-four  hours,  at  a  moderate 
temperature,  and  measuring  the  number  of  divisions 
occupied  by  the  cream. 

Another  method  proposed  by  Daubrawa  for  the  rapid 
determination  of  the  quality  of  milk  consists  in  mixing 
it  with  two  volumes  of  alcohol  of  sp.  gr.  0*833,  filtering 
off  the  butter  and  casein  (which  may  be  dried  and 
weighed),  and  taking  the  specific  gravity  of  the  filtrate. 
Every  increase  of  "004  in  the  specific  gravity  above 
0*905  (the  sp.  gr.  of  the  mixture  of  alcohol  with  the 
water  of  the  milk)  indicates  1  per  cent,  of  milk-sugar. 
For  example,  if  the  specific  gravity  of  the  filtrate  be 
0*922,  there  would  be  4*25  per  cent,  of  milk  sugar,  for 
0*922— 0*905= *017,  and  *017=-004=4:-25.  The  result 
may  be  controlled  by  evaporating  the  spirit,  converting 
the  milk-sugar  into  grape-sugar  by  boiling  with  a  little 
dilute  sulphuric  acid,  rendering  the  solution  alkaline  by 
potash,  and  determining  the  sugar  by  the  standard  cop- 
per solution  (352). 

659.  It  occasionally  happens  that  the  milk  exposed 
for  sale  is  the  produce  of  an  unhealthy  animal.  Such 
milk  has  usually  some  peculiarity  of  taste  or  smell,  and 
also  a  slightly  viscid  and  unnatural  appearance;  on  being 
examined  under  the  microscope,  too,  it  will  probably  be 
found  to  contain  pus  or  mucus  corpuscles,  or  to  present 
other  appearances  differing  from  those  of  the  healthy 
secretion. 


^     BILK.  239 


CHAPTER  V. 

BILE. 

659a.  THE  bile  consists  essentially  of  an  aqueous  solu- 
tion of  two  salts,  known  as  cholate  (or  glycocholate)  and 
choleate  (or  taurocholate)  of  soda.  It  is  generally,  but 
not  always,  alkaline. 

Bile  is  remarkable,  among  the  secretions  of  the  animal 
body,  for  the  large  proportion  of  carbon  which  it  con- 
tains. Cholic  acid  (HO,C52H42NOn)  contains  67  per  cent., 
and  choleic  acid  (HO,C52IJ44N013S2)  6O5  per  cent,  of  car- 
bon. There  are  also  present  in  bile  a  quantity  of  mucus, 
to  which  it  owes  its  viscidity,  a  peculiar  coloring  matter, 
and  minute  quantities  of  cholesterine,  oleine,  margarine, 
and  lecithine  (a  phosphorized  fat  discovered  in  bile  by 
Gobley,*  and  also'found  in  serum),  together  with  chloride 
of  sodium,  and  alkaline  and  earthy  phosphates. 

Cholic  acid. — To  isolate  this  acid,  the  bile  is  evaporated 
to  dryness,  the  residue  dried  at  250°  Fahr.  and  digested, 
in  the  cold,  with  absolute  alcohol.  The  coloring  matter 
is  precipitated  from  the  alcoholic  solution  by  the  gradual 
addition  of  ether,  and  the  clear  solution  decanted  from 
the  deposit  is  mixed  with  more  ether,  when  it  gradually 
deposits  tufts  of  needles  consisting  of  the  cholates  of 
potash  and  soda.  After  having  been  washed  with  a  mix- 
ture of  absolute  alcohol,  with  TJ^th  ether,  the  crystals  are 
dried  in  vacuo,  dissolved  in  a  little  water,  and  decom- 
posed by  dilute  sulphuric  acid,  when  cholic  acid  slowly 
separates  in  silky  crystals,  which  are  sparingly  soluble 
in  cold  water,  and  in  ether,  but  readily  in  alcohol. 

When  cholic  acid  is  boiled  with  dilute  hydrochloric 

*  Journ.  of  Pharm.,  xxx.  241.  Strecker  Las  recently  discovered 
lactic  acid  in  bile,  together  with  a  new  alkaline  base — Cholinc  CIOH,3N02. 


240  BILE. 

acid,  it  assimilates  the  elements  of  water,  and  is  decom- 
posed into  choloidic  acid  and  glycocine  (or  sugar  of 
gelatine): — 

Cholic  acid.  Choloidic  acid.        Glycocine. 

HO,C52H42NOn  +  HO  ^C^H~0^  +  C^l\. 

Choleic  acid. — This  acid  is  not  nearly  so  abundant  in 
the  bile  as  the  preceding.  In  order  to  obtain  it,  the  bile 
is  mixed  with  water,  and  acetate  of  lead  added  to  separate 
the  mucus,  the  cholic,  and  the  fatty  acids.  From  the  fil- 
tered liquid,  the  color  is  removed  by  adding  tribasic 
acetate  of  lead  till  the  precipitate  is  white,  and  after  fil- 
tration, the  choleic  acid  is  precipitated  by  adding  more 
tribasic  acetate  of  lead  and  ammonia.  The  lead  salt  is 
dissolved  in  alcohol,  filtered,  reprecipitated  by  water,  and 
decomposed  by  sulphuretted  hydrogen.  The  solution 
filtered  from  the  sulphide  of  lead  is  evaporated,  when  it 
leaves  the  choleic  acid. 

When  boiled  with  acids,  choleic  acid  is  decomposed, 
with  the  concurrence  of  the  elements  of  water,  into  a 
new  acid,  and  a  peculiar  crystalline  body  called  taurine: — 

Choleic  acid.  Cholalic  acid.  Taurine. 


HO,C52H44N013S2-f  2HO  =  HO,C48H3909-f  C4H7N06S2. 

Taurine,  which  has  also  been  found  in  the  kidneys  and 
in  the  lungs  of  the  ox,  is  conspicuous  among  organic 
substances,  for  the  large  amount  of  sulphur  which  it 
contains  (25'6  per  cent.).  It  may  be  prepared  in  quan- 
tity by  mixing  bile  with  hydrochloric  acid,  filtering  it 
from  the  mucus,  and  boiling  for  some  hours.  The  clear 
liquid  having  been  poured  off  from  the  resinous  deposit, 
is  evaporated  to  a  small  bulk  on  the  water-bath.  The 
solution  is  drained  from  the  crystals  of  chloride  of  sodium, 
and  mixed  with  six  volumes  of  alcohol.  On  standing, 
prismatic  crystals  of  taurine  are  deposited,  and  may  be 
recrystallized  from  water  in  order  to  purify  them.  It  is 
insoluble  in  absolute  alcohol  and  ether,  and  not  very 
soluble  in  cold  water.  It  may  be  identified  by  the  odor 
of  sulphurous  acid  when  a  crystal  is  heated  on  platinum 
full. 

Coloring  matter  of  bile. — Two  coloring   matters  have 


BILK.  241 

been  obtained  from  bile,  one  of  which,  Uliverdine,  is 
easily  soluble  in  alcohol,  whilst  biliphceine  dissolves  with 
difficulty.  In  order  to  separate  them,  Briicke  recom- 
mends that  the  bile  be  well  shaken  with  chloroform, 
which  extracts  the  biliphaoine.  On  evaporating  the 
chloroform,  and  treating  the  residue  with  strong  alcohol, 
the  coloring  matter  is  left  in  red  crystals,  which  may  be 
purified  by  washing  with  alcohol  and  ether.  If  biliphss- 
ine  be  dissolved  in  carbonate  of  soda,  the  solution  oxi- 
dized by  exposure  to  air,  and  neutralized  with  hydro- 
chloric acid,  a  precipitate  of  biliverdine  is  obtained. 

In  Bright's  disease,  it  is  said  that  albumen  and  urea 
have  been  found  in  bile. 

Sugar-forming  substance  in  the  liver. — If  a  fresh  liver  be 
cut  into  thin  slices,  heated  with  a  small  quantity  of  water, 
the  solution  filtered,  evaporated  to  a  small  bulk,  and 
mixed  with  a  large  excess  of  glacial  acetic  acid,  a  white 
flocculent  precipitate  is- obtained  which  has  the  composi- 
tion Cj2H10O10*  (Kekule*).  This  substance,  which  resem- 
bles starch  in  some  of  its  properties,  as  well  as  in  its 
composition,  has  been  called  animal  amyloid,  'hepatine, 
and  glycogene.  Like  starch,  it  is  converted  into  grape- 
sugar  when  boiled  with  dilute  acids,  but  it  gives  a  dark 
brown-red,  instead  of  a  blue  color,  with  iodine.  It  dis- 
solves in  water,  giving  a  strongly  opalescent  fluid  which 
is  precipitated  by  alcohol.  Sugar  is  also  found  in  the 
decoction  of  liver,  but  it  is  doubtful  whether  it  exists  in 
the  organ  during  life,  or  results  from  a  post-mortem  con- 
version of  the  glycogene.  This  substance  has  also  been 
obtained  in  the  milky  fluid  resulting  from  the  injection 
of  water  into  the  liver  in  preparing  it  for  the  ordinary 
process  of  injection. 

*  According  to  Pelouze,  C12HnO,,+HO. 


21 


242  JUICE    OF    FLESH. 


CHAPTER  VI. 

JUICE  OF  FLESH. 

IF  a  few  pounds  of  finely  divided  flesh  be  digested  for 
a  short  time  in  cold  water,  and  afterwards  well  squeezed 
in  a  muslin  bag,  a  reddish  acid*  liquid  is  obtained,  con- 
taining a  little  blood,  together  with  the  constituents  of 
the  juice  of  flesh,  viz.,  albumen,  kreatine,  kreatinine, 
sarcine,  inosite;  lactic  acid,  butyric  acid,f  phosphoric 
acid,  in  combination  with  potash,  lime,  and  magnesia; 
and  chloride  of  potassium  with  a  little  chloride  of  sodium. 

Kreatine  (C8H9N304,2Aq).  To  extract  this  substance, 
the  above  infusion  is  heated  in  a  water-bath  until  the 
whole  of  the  albumen  is  coagulated  :  it  is  then  strained, 
and  mixed  with  baryta-water  until  it  is  alkaline  to 
turmeric  paper.  The  precipitate  (phosphates  of  baryta, 
lime  and  magnesia)  is  filtered  off,  and  the  solution  evapo- 
rated to  a  syrup.  After  standing  for  a  few  days,  it  will 
deposit  prismatic  crystals  of  kreatine,  which  may  be 
purified  by  recrystallization,  with  the  use  of  a  little 
animal  charcoal. 

1000  parts  of  beef  yielded  about  0*7  of  kreatine,  1000 
parts  of  cod-fish,  1'3  parts,  and  1000  of  fowl  about  3 
parts.  Human  flesh  is  said  to  be  particularly  rich  in 
kreatine. 

Kreatine  has  no  alkaline  reaction,  but  is  capable  of 
forming  crystalline  salts  with  acids.  It  dissolves  in  75 
parts  of  cold,  and  in  much  less  boiling  water.  It  is  very 
slightly  soluble  in  alcohol,  and  insoluble  in  ether. 

A  pure  solution  of  kreatine  will  not  give  any  precipi- 
tate with  solution  of  chloride  of  zinc,  but  if  the  solution 

*  According  to  Du  Bois  Raymond,  the  juice  of  the  flesh  is  naturally 
alkaline,  but  becomes  acid  very  speedily  after  death. 

f  Scherer  has  also  found  formic  and  acetic  acids  in  the  juice  of  flesh. 


JUICE    OF    FLESH.  243 

be  previously  boiled  for  some  time,  kreatinine  is  formed, 
which  yields,  with  chloride  of  zinc,  a  granular  crystalline 
precipitate  :  — 

Ereatine.  Krcatinine. 

C8H9N304  +  2HO  ==  C8H7N^? 

The  conversion  is  much  accelerated  by  the  addition  of 
a  little  hydrochloric  or  sulphuric  acid. 

If  kreatine  be  dissolved  in  water  and  boiled  with  10 
parts  of  crystallized  baryta,  as  long  as  any  ammonia  is 
disengaged,  it  yields  a  new  base,  sarcosine,  which  may  be 
obtained  in  prismatic  crystals  by  saturating  the  solution 
with  carbonic  acid  gas,  boiling  to  precipitate  the  excess 
of  baryta,  and  evaporating  the  filtered  liquid  to  a  small 
bulk:— 

Kreatine.  Sarcoslno.  Urea. 


The  urea,  which  is  the  other  product  of  this  decomposition 
of  kreatine,  is  decomposed  by  the  ebullition  with  baryta 
into  carbonic  acid  and  ammonia. 

Kreatinine.  If  the  liquid  from  which  the  crystals  of 
kreatine  were  deposited  be  mixed  with  a  strong  solution 
of  chloride  of  zinc,  and  set  aside,  crystals  of  the  compound 
of  kreatinine  with  chloride  of  zinc  will  be  separated.  The 
preparation  and  properties  of  kreatinine  have  been  de- 
scribed under  the  head  of  urine  (30a). 

Sarcine  (C10H4N4Oa).  To  obtain  this  base,  the  mother- 
liquor  from  the  crystals  of  kreatine  is  diluted,  and  mixed 
with  a  dilute  solution  of  acetate  of  copper.  The  precipitate 
is  washed,  suspended  in  water,  and  decomposed  by 
sulphuretted  hydrogen  ;  after  filtering  from  the  sulphide 
of  copper,  the  solution  is  gently  heated  on  a  water-bath 
to  expel  the  excess  of  sulphuretted  hydrogen,  and  boiled 
with  hydrated  oxide  of  lead  to  remove  the  coloring  matter. 

After  another  filtration,  sulphuretted  hydrogen  is  again 
passed  through  the  solution,  the  sulphide  of  lead  filtered 
off,  and  the  filtrate  evaporated  to  a  small  bulk,  when  it 
deposits  crystals  of  sarcine. 

This  substance,  like  kreatine,  is  a  weak  base,  forming 
salts  with  acids.  It  is  much  less  soluble  in  water  than 
kreatine,  requiring  300  parts  of  cold  and  78  parts  of 


244  JUICE    OF    FLESH. 

boiling  water.  It  is  much  more  sparingly  soluble  in 
alcohol. 

The  composition  of  sarcine  is  the  same  as  that  of  hy- 
poxanthine^  another  basic  substance  which  has  been  found 
in  the  spleen. 

Inosite  (C12H12O12,4Aq).  This  substance,  as  well  as  inosic 
acid  (HO,C10H6N2O10)  does  not  appear  to  be  so  invariably 
present  in  the  juice  of  flesh  as  kreatine  is.*  In  order  to 
extract  it,  if  present,  from  the  mother-liquor  after  the 
separation  of  the  kreatine,  dilute  sulphuric  acid  is  added, 
in  quantity  exactly  sufficient  to  precipitate  the  baryta, 
and  the  filtered  liquid  is  well  shaken  with  ether,  which 
removes  the  lactic  acid.  To  the  aqueous  liquid,  alcohol 
is  then  added  in  successive  portions ;  the  first  addition 
causes  a  precipitation  of  sulphate  of  potash  and  other  salts, 
and  after  separating  these  and  a  further  addition  of 
alcohol,  small  crystals  of  inosite  are  deposited. 

This  body  is  remarkable  for  its  sweet  taste,  and  for 
having,  when  dried  at  212°,  the  same  composition  as  grape- 
sugar  dried  at  that  temperature  (C12H12O1?).  It  differs 
from  that  substance,  however,  in  not  reducing  the  oxide 
of  copper  in  alkaline  solution  to  the  state  of  suboxide,  and 
in  not  giving  a  brown  solution  when  boiled  with  potash. 
Neither  can  it  be  made  to  undergo  the  vinous  fermen- 
tation. Inosite  is  readily  dissolved  by  water,  but  is 
insoluble  in  absolute  alcohol  and  in  ether.  It  is  said  to 
exist  to  the  extent  of  }  per  cent,  in  unripe  beans. 

Lactic  ac^(2HO,C12HIOO10).  The  lactic  acid  extracted, 
as  described  above,  by  ether,  from  the  juice  of  flesh,  is 
commonly  called  sarco-lactic  acid,  to  distinguish  it  from 
ordinary  lactic  acid  obtained  by  the  fermentation  of  milk- 
sugar  (621).  Although  the  properties  of  both  varieties 
of  lactic  acid  in  the  free  state  are  similar,  their  salts  are 
not  precisely  so.  The  sarco-lactate  of  zinc  has  the  form  ula, 
2ZnO,C12H10O10,4Aq,  whilst  the  ordinary  lactate  of  zinc 
contains  6Aq.  Again,  the  sarco-lactate  of  lime  is  2CaO, 
C12H10010,8Aq,  and  the  ordinary  lactate,  which  is  also  the 
more  soluble  in  water,  contains  lOAq. 

*  It  was  originally  obtained  from  the  heart,  but  has  recently  been 
found  in  the  kidneys,  liver,  spleen,  and  lungs  of  the  ox. 


MUCUS.  245 

.  The  lactic  acid  is  obtained  by  evaporating  the  ethereal 
solution,  as  a  syrupy  acid  liquid,  which  does  not  crystallize, 
and  is  best  characterized  by  boiling  it  with  a  few  zinc- 
filings,  when  the  lactate  of  zinc  will  be  formed,  which 
deposits  in  sparingly  soluble  crystalline  crusts. 

Butyric  add  (HO,C3H7O3).  By  acidulating  the  mother- 
liquor  from  the  kreatine  with  sulphuric  or  hydrochloric 
acid,  and  distilling,  a  very  dilute  solution  of  butyric  acid 
is  obtained.  The  acid  may  be  identified  by  its  odor  of 
rancid  butter,  and  in  order  to  obtain  it  in  a  pure  state, 
the  acid  distillate  from  a  large  quantity  of  flesh  must  be 
neutralized  with  baryta  and  evaporated,  when  butyrate 
of  baryta  crystallizes  out.  By  dissolving  this  in  a  little 
water  and  adding  just  enough  sulphuric  acid  to  precipitate 
the  baryta,  a  concentrated  solution  of  the  acid  may  be 
obtained.  By  introducing  into  this,  in  a  tube,  fragments 
of  fused  chloride  of  calcium,  the  butyric  acid  is  separated 
and  rises,  as  an  oily  layer,  to  the  surface,  whence  it  may 
be  drawn  off,  and  purified  by  distillation  with  a  little 
more  chloride  of  calcium. 


CHAPTER  VII. 

MUCUS. 


SECTION  I. 
General  Characters  of  Mucus. 

660.  HEALTHY  mucus,  which  is  secreted  by  the  mucous 
membrane  with  which  the  internal  surfaces  of  the  several 
parts  of  the  body  are  covered,  is  a  semi-fluid  viscid  sub- 
stance, the  general  appearance  of  which  is  well  known. 
It  is  sometimes  so  thin  and  limpid  as  almost  to  resemble 
water  in  appearance;  while  at  others,  and  more  commonly, 
it  is  tough  and  extremely  tenacious,  becoming  stringy 
when  attempted  to  be  drawn  out.  When  thin  and  watery, 
it  is  nearly  transparent  and  colorless :  the  most  viscid 


2-16  MUCUS. 

forms,  however,  being  turbid  or  opaque,  and  usually  of 
a  pale  yellowish  or  grayish  color.  It  is  generally  alkaline 
to  test  paper,  insoluble  in  water,  and  somewhat  heavier 
than  that  fluid;  so  that  when  placed  in  water  it  gradually 
sinks  to  the  bottom,  unless  it  is  buoyed  up  by  entangled 
air-bubbles.  The  mucus  obtained  from  the  several  parts 
of  the  body  differs  considerably  in  appearance,  and  prob- 
ably also  in  chemical  composition.  When  dry  it  is  hard 
and  friable,  resembling  horn  in  appearance;  the  dry  mass, 
on  being  digested  in  water,  gradually  swells  up,  and  par- 
tially reassumes  its  former  appearance. 

661.  When  mucus  is  examined  under  the  microscope, 
with  a  power  of  about  200  diameters,  it  is  found  to  con- 
tain numerous  round  or  oval  granular  corpuscles,  together 
with  epithelial  scales  (Fig.  5),  entangled  in  a  more  or  less 
viscid  fluid,  to  which  latter  the  peculiar  tenacious  cha- 
racter of  mucus  appears  to  be  due.     Mucus,  therefore, 
consists  of  two  distinct  portions:   the  solid  corpuscles 
with  epithelial  scales,  and  the  fluid  with  which  they  are 
surrounded.     Under  favorable  circumstances,  and  with  a 
high  magnifying  power,  the  fluid  portion  appears  to  be 
filled  with   extremely  minute    molecular   particles,  the 
nature  of  which  is  not  clearly  understood. 

662.  The  size  of  the  mucus  corpuscles  varies   con- 
siderably, the  average  diameter  being  about  s^^th  of 
an  inch.     Their  surfaces  are  granular,  similar  to  those  of 
pus ;  and  when  treated  with  dilute  acetic  acid,  the  ex- 
terior covering  loses  its  granular  appearance,  and  becomes 
transparent,  rendering  visible  from  one  to  five  internal 
nuclei.     The  same  effect  is  produced  by  dilute  oxalic  and 
tartaric  acids ;  but  the  dilute  mineral  acids  cause  little  or 
no  change. 

663.  Mucus  appears  to  contain  in  its  composition  the 
following  substances :  mucus  corpuscles,  epithelial  scales, 
mucin,  traces  of  extractive  matters  and  fat,  sometimes  a 
small  trace  of  albumen,  and  saline  matters;  which  latter 
consist  of  alkaline  chlorides  and  lactates,  phosphate  of  lime, 
and  traces  of  carbonate  of  soda.    The  mucin,  to  which  the 
peculiar  tenacious  character  of  mucus  appears  to  be  due, 
is  insoluble  in  pure  water,  and  is  probably  held  in  solu- 
tion in   the  fluid  portion  of  the  mucus,  by  the  small 


QUANTITATIVE    ANALYSIS    OF    MUCUS.         247 

excess  of  alkali  usually  present;  it  separates  in  the  form 
of  a  white  coagulum  when  mucus  is  treated  with  water, 
and  still  more  completely  when  neutralized  with  dilute 
acetic  acid.  The  minute  traces  of  fat  found  in  mucus 
probably  exist  in  the  corpuscles  though  the  exact  chemi- 
cal nature  of  these  is  by  no  means  clearly  ascertained. 

SECTION  II. 
Quantitative  Analysis  of  Mucus. 

664.  The  quantitative  determination  of  the  principal 
constituents  of  mucus  may  be  made  in  the  following 
manner.     The  mucus  intended  for  analysis  is  first  divided 
into  two  portions,  A  and  B;  the  first,  A,  being  about  one- 
quarter,  and  the  second,  B,  about  three-quarters  of  the 
whole.     Both  portions  are  to  be  weighed  in  counterpoised 
capsules,  that  containing  A  being  of  platinum,  and  eva- 
porated to  dryness  on  a  chloride  of  calcium  bath,  at  a 
temperature  of  about  220°. 

665.  Treatment  of.  the  portion  A. — This  portion,  after 
being  dried  until  it  ceases  to  lose  weight,  is  to  be  accu- 
rately weighed.     The  weight  of  the  dry  residue  gives 
the  amount  of  SOLID  MATTER  in  the  quantity  of  mucus 
evaporated,  while  the  loss  represents  the  amount  of  WATER. 

666.  The  proportion  of  these  and  the  other  ingredients, 
contained  in  1000  parts  of  the  mucus,  may  in  each  case 
be  estimated  by  the  following  calculation: — 

("Weight   of"!  rWt.    of  each  con-1  f  Proportion  of  that  ] 

mucus      I  J  stituent  contained  I  .     ,  ftnft    I    constituent  con-   ! 

T  before  eva-  [  1  in  the  quantity  of  f  '  1    tained   in   1000    [ 

I   poration    J  [  mucus  employed.  J  [  parts  of  mucus,  j 

667.  The  dry  residue  is  then  to  be  incinerated   at  a 
low  red  heat,  until  the  ash  becomes  white,  or  nearly  so. 
The  weight  of  the  ash  will  then  represent  the  amount  of 
SALINE  MATTER  in  the  quantity  of  rnucus  used ;  from 
which  the  proportion  present  in  1000  parts  may  be  calcu- 
lated as  before  (666). 

668.  Treatment  of  the  portion  B.— The  dry  residue  left 
after  evaporation  (664),  is  to  be  removed  from  the  capsule, 
and  reduced  to  fine  powder  in  a  mortar.     It  is  then 
boiled  with  successive  small  portions  of  ether,  which  will 


248  MORBID    MUCUS. 

dissolve  out  the  fat  (545).  The  ethereal  solution  is  eva- 
porated to  dryness  on  a  water-bath,  when  the  weight  of 
the  residue  will  indicate  the  amount  of  FAT  in  the  quan- 
tity of  mucus  employed ;  from  which  the  proportion  in 
1000  parts  may  be  estimated  as  before  (666). 

669.  The  residue  which  proved  insoluble  in  the  ether 
(668)  is  to  be  boiled  with  a  little  alcohol,  after  which  the 
alcoholic  solution  is  to  be  evaporated  to  dryness,  and  the 
dry  residue  weighed.     This  is  then  incinerated,  and  the 
weight  of  the  ash,  deducted  from  that  of  the  dry  extract, 
will  give  the  amount  of  ALCOHOL  EXTRACTIVE,  with  the 
lactic  acid  of  the  lactates,  in  the  quantity  of  mucus  used ; 
which  may  be  corrected,  as  before,  for  1000  parts  (666). 

670.  The  portion  of  the  residue  which  proved  insoluble 
in  the  alcohol  (669)  is  to  be  dried  and  weighed ;  the  weight 
indicating  the  amount  of  MUCIN,  together  with  cellular 
matter,  and  probably  traces  of  albumen,  in  the  quantity 
of  mucus  employed ;  from  which  the  proportion  present 
in  1000  parts  of  rnucus  may  be  calculated,  as  in   the 
former  cases  (666). 

671.  According  to  Nasse,  the  composition  of  fresh  pul- 
monary mucus  is  as  follows: — 

Water 955-520 

Solid  constituents 44-480 

Mucin,  with  a  little  albumen  ....  23-754 

Water  extract 8-006 

Alcohol  extract                 .         .         .         .         .  1-810 

Fat 2-887 

Chloride  of  sodium 5-825 

Sulphate  of  soda 0-400 

Carbonate  of  soda 0-198 

Phosphate  of  soda 0-080 

Phosphate  of  potash,  with  traces  of  iron         .  0-974 

Carbonate  of  potash 0-291 

Silica,  and  sulphate  of  potash         .         .         .  0-255 


SECTION  III. 
Morbid  Mucus. 

672.  The  characters  of  mucus  secreted  during  disease 
are  usually  more  or  less  different  from  those  of  the  nor- 
mal secretion,  and  an  admixture  of  foreign  matters  fre- 
quently alters  its  appearance  considerably.  Pus,  for 


GENERAL    CHARACTERS    OF    PUS.  249 

instance,  when  mixed  with  it,  diminishes  its  tenacity, 
owing  to  the  mucin  being  present  in  smaller  proportion 
(663);  and  when  the  liquid  portion  of  mucus  containing 
an  admixture  of  pus  is  tested  for  albumen  (254,  677),  a 
considerable  amount  of  that  substance  may  usually  be 
detected ;  since  the  liquor  puris,  or  liquid  portion  of  pus, 
contains  a  comparatively  large  quantity  of  albumen,  but 
no  mucin.  Our  means  of  detecting  the  presence  of  minute 
traces  of  pus  in  mucus- are  very  imperfect;  the  decided 
presence  of  albumen  in  the  purulent  secretion  is,  indeed, 
almost  the  only  test,  since  the  microscopic  characters  of 
the  corpuscles  appear  to  be  very  similar  (249). 

673.  The  morbid  mucus  expectorated  in  pulmonary 
disease  frequently  contains,  besides  pus,  red  blood  cor- 
puscles, minute  globules  of  fat,  fragments  of  tuberculous 
matter,  and  other  abnormal  substances,  most  of  which 
may  generally  be  detected  without  difficulty  under  the 
microscope.  The  indications  afforded  by  a  careful  micro- 
scopic examination  of  such  expectorations,  indeed  may 
often  lead  to  results  in  diagnosis,  of  great  importance  to  the 
practical  physician. 


CHAPTER  VIII. 
PUS. 


SECTION  I. 
General  Characters  of  Pus. 

674.  Pus  is   the  peculiar  semi-fluid  matter  which  is 
formed  in  abscesses,  and  in  other  kinds  of  wounds.     In 
common  language,  a  considerable  variety  of  substance^, 
more  or  less  resembling  each  other  in  appearance,  though 
differing  in  many  respects,  are  included  under  the  name 
of  pus  ;    and  hence  it  has  been  found  necessary  to  distin- 
guish the  normal  secretion  by  the  name  of  true  or  genuine 
pus;  the  other  substances  being  called  spurious  or  false  pus. 

675.  Normal  pus  is  a  thick  creamy- looking  fluid,  per- 


250  GENERAL    CHARACTERS    OF    PUS. 

fectly  opaque,  and  usually  of  a  pale  yellow  or  greenish 
color.  It  possesses  little  or  no  tenacity,  and  may  conse- 
quently be  poured  in  separate  drops  ;  in  which  respect  it 
differs  essentially  from  mucus,  which,  in  color  and 
general  appearance  it  often  much  resembles.  Its  specific 
gravity  is  usually  about  1030  or  1033,  so  that  it  sinks  in 
water  ;  and  if  shaken  up  with  that  fluid,  mixes  uniformly 
with  it.  The  mixture,  after  standing  a  short  time, 
gradually  deposits  a  sediment,  consisting  of  pus-corpus- 
cles (678).  It  is  most  commonly  neutral  to  test  paper, 
but  is  also  occasionally  met  with  slightly  acid  or  alkaline. 

676.  Like  mucus,  pus  consists  of  a  clear  fluid  portion 
or  serum,  in  which  float  innumerable  minute   granular 
corpuscles,  which  latter  appear  to  be  almost  precisely  the 
same  as  those  contained  in  mucus,  and  when  examined 
under  the  microscope,  exhibit  the  same  granular  appear- 
ance.    The  liquid  portion  of  pus,  or  liquor  puris,  how- 
ever, differs  essentially  from  that  of  mucus,  and  contains 
the    following  substances  in  solution,  which,  it  will  be 
seen,  are  nearly  the  same  as  those  held  in  solution  in  the 
serum  of  the  blood  (568) — viz.,  albumen,  together  with  a 
peculiar  compound  called  pyin,  or  tritoxide  of  protein 
(which  is  soluble  in  water,  and  precipitated  by  acetic  acid), 
fat,  cholesterin,  extractive  matters,  and  inorganic  salts.* 
These  latter  consist,  for  the  most  part,  of  chloride  of 
sodium,  with  small  quantities  of  phosphate,  sulphate,  and 
carbonate   of    soda;    the    chlorides   of    potassium    and 
calcium ;  phosphates  and  carbonates  of  lime  and  magnesia; 
and  traces  of  peroxide  of  iron. 

677.  The  presence  of  these  matters  in  the  liquor  puris 
may  be   shown  by  placing  some  pus  in  a  tall  narrow 
glass,  and  allowing  it  to  stand,  in  order  to  give  the  cor- 
puscles time  to  subside  ;  after  which,  a  little  of  the  clear 
liquid  may  be  drawn  off  with  a  pipette.     On  boiling  a 
few  drops  of  this  in  a  test-tube,  the  albumen  becomes 
c'oagulated,  and  separates  from  the  liquid  ;  after  which 
the  pyin  may  be  thrown  down  in  the  form  of  a  white 
flocculent  precipitate,  by  adding  a  little  acetic  acid.f  The 

*  Leucine  (C12HI3N04)  has  also  been  found  in  pus. 
f  Pyin  is  precipitated  by  chloride  of  mercury  and  by  acetate  of 
lead,  which  is  not  the  case  with  mucin. 


GENERAL    CHARACTERS    OF    PUS.  251 

liquid  may  then,  if  necessary,  be  tested  for  the  several 
inorganic  salts  above  enumerated  (676,  490). 

678.  The  pus-corpuscles,  though  quite  invisible  to  the 
naked  eye,  may  be  distinguished  under  the  microscope 
with  a  magnifying  power  of  from  fifty  to  one  hundred 
diameters;   a  considerably 

higher  power,  however,  is  re- 
quired  for  exhibiting  their 
peculiar  granular  structure 
(Fig.  74,  a).  The  size  of  these 
corpuscles  varies  considerably, 
being  commonly  about j^^th 
of  an  inch  in  diameter.  They 

,  .        .      .  ,   ,        J  Pus-corpuscles,  magnified  400 

are  nearly  spherical ;  and  have  diameters. 

a   very   pale   yellowish  color, 

which  is  scarcely  perceptible,  unless  several  of  them  are 
aggregated  together.  Being  slightly  heavier  than  the 
liquor  puris  with  which  they  are  surrounded,  they 
gradually  subside  to  the  bottom,  leaving  the  fluid  portion 
nearly  clear.  Minute  globules  of  fat  may  usually  be 
detected,  mixed  with  the  corpuscles. 

679.  The  pus-corpuscles,  when  treated  with  liquids  of 
different  densities,  exhibit  the  phenomena  of  endosmosis 
and    exosmosis,    somewhat    similar  *to    those    already 
described  as  taking  place  in  the  corpuscles  of  the  blood 
(456);    increasing  in  size  when  the  external  liquid,  such 
as  pure  water,  is  of  lower  density,  and  collapsing  when 
it  is  of  higher  density,  than  the  fluid  contained  in  them. 
When  treated  with  dilute  acetic  acid,  the  external  cover- 
ing  becomes   transparent,  and    exhibits  one   or    more 
internal  nuclei  (Fig.  74,  6). 

680.  When  mixed  with  a  solution  of  ammonia  or  pot- 
ash, pus  loses  its  fluidity,  and  assumes  a  jelly-like  appear- 
ance, which  is  highly  characteristic,  and  is  employed  to 
distinguish  it  from  mucus,  which  becomes  less  tenacious 
than  before  when  treated  with  alkalies.     A  somewhat 
similar  effect  is  produced  also  by  the  alkaline  carbonates, 
and  certain  other  salts. 

681.  Although  the  general  appearance  and  characters 
of  pus  are  usually  sufficiently  marked  to  enable  us  to 
identify  it,  it  is  always  advisable,  in  cases  where  any 


252  QUANTITATIVE    ANALYSIS    OF    PUS. 

doubt  exists,  to  submit  it  to  microscopical  examination ; 
since  occasionally  we  meet  with  fluids  containing  a  large 
quantity  of  epithelium  and  other  products,  which,  in. 
appearance,  closely  resemble  pus,  though  differing  entirely 
in  composition  from  that  substance,  and  containing  no 
trace  of  the  characteristic  pus-corpuscles  (678).  The  form 
of  the  corpuscles  is  found  to  vary  considerably  under 
certain  pathological  conditions;  but  there  may  generally 
be  traced  sufficient  resemblance  to  the  normal  corpuscles 
to  enable  us  to  distinguish  them  from  other  matters. 
The  modes  of  distinguishing  between  pus  and  mucus, 
have  been  already  noticed  in  paragraphs  248,  &o. 

681a.  Blue  pus. — In  certain  rare  cases,  the  bandages 
upon  which  the  pus  has  been  discharged  assume  a  blue 
color.  By  treating  them  with  water,  and  agitating  the 
aqueous  solution  with  chloroform,  Fordos  has  extracted 
a  blue  crystalline  coloring  matter,  which  he  calls  pyocy- 
anine.  It  is  soluble  in  water,  alcohol,  and  ether;  its 
color  is  changed  to  red  by  acids,  but  the  blue  is  restored 
by  alkalies. 

SECTION  II. 
Quantitative  Analysis  of  Pus. 

682.  The  quantitative  analysis  of  pus  may  be  made  in 
the  following  manner :  Two  portions  of  the  fluid  are  to 
be  weighed  out ;  the  first,  A,  in  a  small  counterpoised 
flask ;  and  the  second,  B,  in  a  counterpoised  or  weighed 
evaporating  dish. 

683.  Treatment  of  the  portion  A. — The  portion  A,  after 
being  weighed  in  a  flask,  is  to  be  boiled  with  successive 
small  quantities  of  strong  or  absolute  alcohol,   which 
must  be   separated   while   hot,   either  by  filtration   or 
decantation,  from  the  insoluble  portion.     The  alcoholic 
solution  is  then  set  aside  to  cool,  and  allowed  to  stand 
a  few  hours,  in  order  that  the  fat  may,  for  the  most  part, 
crystallize  out.     The  cold  alcoholic  liquid  is  then  poured 
off,  and  the  solid  matter  dried  and  weighed ;  when  the 
weight  thus  obtained  will  represent  the  amount  of  FAT 
in  the  quantity  of  pus  employed  in  the  experiment. 

684.  The  cold  alcoholic  liquid  (683)   is   now  to   be 


QUANTITATIVE    ANALYSIS    OF    PUS.  253 

evaporated  to  dryness,  on  the  water-bath,  in  a  counter- 
poised platinum  capsule,  and  the  dry  residue,  after  being 
weighed,  is  incineratedv  The  weight  of  the  ash  is  then 
ascertained,  when  the "  difference  between  the  weight 
before  and  after  incineration  will  represent  the  quantity 
of  EXTRACTIVE  MATTER  (together  with  traces  of  fat  which 
had  not  separated  from  the  cold  alcohol),  in  the  portion 
of  pus  employed. 

685.  The  residue  which  proved  insoluble  in  the  boiling 
alcohol  (683),  is  to  be  dried  on  a  water-bath,  and  then 
boiled  with  a  little  water,  which  will  dissolve  out  the 
pyin,  and  at  the  same  time  cause  the  coagulation  of  the 
albumen.     The  aqueous  solution  thus  obtained  is  to  be 
separated  from  the  insoluble  portion;  evaporated  to  dry- 
ness  in  a  platinum  capsule  on  a  water-bath;   and  the 
weight  of  the  dry  residue  having  been  noted,  it  is  to  be 
incinerated.     The  difference  between  the  weight  of  the 
dry  residue  previous  to  incineration,  and  that  of  the  in- 
organic ash,  represents  the  amount  of  PYIN  in  the  portion 
of  pus  used  in  the  experiment. 

686.  The  matter  which  remained  insoluble  in  the  hot 
water  (685),  is  now  to  be  dried  and  weighed.     The  dry- 
residue  is  incinerated;  and  the  loss  of  weight  which  it 
experiences  during  incineration  will  show  the  amount  of 
ALBUMEN  AND  CORPUSCLES  in  the  quantity  of  pus  operated 
on. 

687.  Treatment  of  the  portion  B. — The  weight  of  this 
portion  having  been  noted,  it  is  to  be  evaporated  to  dry- 
ness  on  a  chloride-of-calcium  bath,  at  a  temperature  of 
about  220°,  the  heat  being  continued  until  it  ceases  to 
lose  weight  on  being  weighed  at  intervals  of  half  an  hour 
or  an  hour.     The  loss  of  weight  during  the  evaporation 
will  then  represent  the  proportion   of  WATER   in    the 
quantity  of  pus  employed ;  while  the  weight  of  the  dry 
residue  shows  the  amount  of  SOLID  MATTER. 

688.  The  dry  residue  is  now  to  be  incinerated  in  a 
platinum  capsule  or  crucible,  until  the  ash  becomes  white 
or  pale  gray.     The  weight  of  the  ash  will  then  show  the 
amount  of  inorganic  SALINE  MATTER  in  the  quantity  of 
pus  used  in  the  experiment. 

689.  The  proportion  of  the  several  constituents  con- 
22 


254 


GENERAL  CHAEACTEES  OF  BONE. 


tained  in  1000  parts  of  pus,  may  then  be  estimated  from 
the  numbers  obtained  in  the  above  experiments,  by  the 
following  calculation: — 


rwt.  of  pus 

<  used  in  the 
t  experiment 


f  Wt.  of  each  "1 

constituent  }• 

obtained.    J 


f  Proportion  of  that ") 

1000    :    4      constituent  in      }- 

[  1000  parts  of  pus.  J 


690.  From  the  analysis  of  Dr.  Wright,  the  composition 
of  pus  appears  to  be  as  follows: — 


Pus  from  Pus  from  a  psoas 
avomica.  abscess. 


Water 

Fatty  matter 

Cholesterin 

Mucus 

Albumen  . 

Lactates,  carbonates,  and 
phosphates  of  soda,  pot- 
ash, and  lime 

Iron  . 

Loss 


894-4 
17-5) 
5.4} 
11-2 

68-5 

9-7 

a  trace. 
3-3 

1000-0 


CHAPTER  IX. 

BONE. 


885-2 

28-8 

6-1 

63-7 

13-5 

2-7 
1000-0 


Pus  from  a 

mammary 

abscess. 

879-4 
2G-5 


83-6 


1000-0 


SECTION  I. 

General  Characters  of  Bone. 

691.  THE  color,  texture,  specific  gravity,  and  general 
characters  of  bone,  differ  very  much  in  different  parts  of 
the  body;  and  the  proportions  of  the  several  chemical 
ingredients  are  also  found  to  vary  considerably.  The 
two  principal  constituents  of  bone  are  cartilage*  and 

*  Called  osseine  by  Fremy,  who  states  that  it  contains  the  same 
proportions  of  carbon,  hydrogen,  nitrogen,  and  oxygen  as  gelatine, 
into  which  it  is  convertible  with  a  facility  which  is  -inversely  as  the 
age  of  the  animal. 


GENERAL    CHARACTERS    OF    BONE.  265 

phosphate  of  lime  (3CaO,PO5) ;  the  proportion  of  the 
former  being  usually  about  29  to  3-i  per  cent.,  and  that 
of  the  latter  from  50  to  60  per  cent,  of  the  entire  bone. 
The  other  substances,  which  are  present  in  smaller  quan- 
tity, are,  carbonate  of  lime  (CaO,C02);  phosphate  of 
magnesia  (3MgO,P05)  ;  fluoride  of  calcium  (CaF) ;  solu- 
ble soda  salts,  chiefly  chloride  of  sodium;  traces  of  the 
oxides  of  iron  and  manganese;  and  fat;  which  lattert 
however,  does  not  belong  strictly  to  the  bone,  but  to  the 
marrow  contained  in  it.  The  presence  of  these  several 
substances  may  be' demonstrated  by  the  following  experi- 
ments. 

692.  The  cartilaginous  matter  of  bone  may  be  obtained 
almost  entirely  free  from  the  saline  and  other  ingredients, 
by  digesting  a  bone  for  a  day  or  two,  at  a  temperature 
not  higher  than  about  50°,  in  dilute  hydrochloric  acid, 
composed  of  about  one  part  of  the  strong  acid  and  five 
parts  of  water.     The  earthy  and  saline  matters  gradually 
dissolve  in  the  acid,  leaving  the  cartilage  unaffected,  and 
still  retaining  the  exact  form  of  the  bone.     In  this  state 
it  is  soft  and  elastic;  becoming,  when  dried,  hard,  some- 
what brittle,  and  horny  in  appearance. 

693.  If  the  cartilage  be  boiled  for  some  time  in  water, 
it  will  almost  wholly  dissolve,  being  converted  into  gela- 
tine (the  glutin  of  some  writers),  leaving  undissolved 
nothing  more  than  a  delicate  network  of  vessels.     The 
aqueous   solution   thus  obtained   becomes,   unless  very 
dilute,  gelatinous  on  cooling. 

694.  The  fat  may  be  separated  by  boiling  a  few  frag- 
ments of  crushed  bone  with  ether,  and  evaporating  the 
ethereal  solution ;  when  the  fat  will  be  left  behind  as  a 
residue. 

695.  The  phosphate  of  lime  and  phosphate  of  magnesia 
may  be  isolated  by  dissolving  a  fragment  of  calcined 
bone*  in  dilute  hydrochloric  acid,  and  supersaturating 
the  acid  solution  with  ammonia;  which  will  throw  down 
a  white  gelatinous  precipitate  of  the  mixed  earthy  phos- 
phates.    If   this   precipitate   be    examined    under   the 

v 

*  A  large  piece  of  bone  may  be  burnt  in  a  clear  fire  till  perfectly 
white. 


256  GENERAL    CHARACTERS    OF    BONE. 

microscope,  it  will  be  found  to  be  chiefly  composed  of 
amorphous  particles  of  phosphate  of  lime,  mixed  with  a 
small  quantity  of  the  crystalline  double  phosphate  of 
ammonia  and  magnesia  (2MgO,NH4O,P05+12Aq),  show- 
ing the  presence  of  phosphate  of  magnesia. 

696.  The  presence  of  carbonic  acid  (carbonate  of  lime) 
may  be  proved  by  the  effervescence  which  ensues  when 
a  fragment  of  uncalcined  bone  is  moistened  with  dilute 
hydrochloric  acid.     If  the  solution,  filtered  from  the  pre- 
cipitate of  earthy  phosphates  (695),  be  tested  with  oxalate 
of  ammonia,  it  will  be  found  still  to  contain  a  considera- 
ble amount  of  lime,  which  existed  in  the  bone  as  carbonate; 
since  that  portion  only  of  the  lime  was  precipitated  by 
the  ammonia,  which  was  in  combination  with  phosphoric 
acid. 

697.  If  calcined  bone,  reduced  to  powder,  be  boiled 
for  some  little  time  in  a  test  tube  or  glass  flask,  with  a 
little  rather  dilute  sulphuric  acid,  consisting  of  about 
equal  parts  of  the  strong  acid  and  water,  the  inner  sur- 
face of  the  glass  will  generally  be  found  to  be  slightly 
corroded,  owing  to  the  disengagement  of  hydrofluoric 
acid  (HF)  by  the  action  of  the  sulphuric  acid  on  the 
fluoride    of    calcium.      CaF  +  HO,S03= CaO,S03+HF. 
This  substance,  however,  does  not  appear  to  be  invariably 
present  in  bone,  and  some  observers  have  been  unable  to 
detect  it. 

698.  The  presence  of  chloride  of  sodium  may  be  shown 
by  boiling  a  little  calcined  bone  reduced  to  powder  with 
water,  filtering  from  the  insoluble  earthy  portion,  and 
testing  a  few  drops  of  the  aqueous  solution  with  nitrate 
of  silver,  which  will  give  an  abundant  precipitate  of  the 
chloride  (AgCl).     By  concentrating  the  rest  of  the  solu- 
tion to  a  small  bulk  and  testing  it  on  platinum  wire  in 
the  blowpipe  flame,  a  yellow  color  will  appear,  showing 
the  presence  of  soda. 

699.  A  little  sulphate  of  soda  may  also  be  detected, 
by  means  of  chloride  of  barium,  in  the  soluble  portion 
of  calcined  bone,  though  no  trace  of  sulphuric  acid  is  to 
be  found  in  it  previous  to  calcination ;  being  produced, 
during  ignition,  by  the  oxidation  of  the  sulphur  con- 
tained in  the  tissues. 


QUANTITATIVE    ANALYSIS    OF    BONE.          257 

SECTION  II. 
Quantitative  Analysis  of  Bone. 

700.  About  three  hundred  grains  of  the  bone  intended 
for  analysis  should  be  first  cleaned  from  adhering  fat, 
periosteum,  and  other  impurities,  and  then  reduced  to 
tolerably  small  fragments  either  by  crushing  or  rasping. 

701.  Treatment  of  the  first  portion. — One  hundred  grains 
of  the  bone  are  to  be  dried  in  a  counterpoised  platinum 
capsule  or  crucible,  on  a  chloride-of-calcium  bath,  at  a 
temperature  of  about  250°,  until  it  ceases  to  lose  weight 
on  being  weighed   at  intervals  of  half  an  hour  or  an 
hour.     The  loss  of  weight  which  it  experiences  during 
desiccation  represents  the  percentage  of  WATER. 

702.  The  dry  mass  is  now  to   be  incinerated  in  the 
capsule  at  a  low  red  heat,  until  the  whole  of  the  organic 
matter  is  burnt  away,  and  the  ash  becomes  throughout 
perfectly  white.     The  weight  of  this  ash  gives  the  per- 
centage of  INORGANIC  MATTER  contained  in   the  bone; 
while  the  loss  during  incineration  represents  the  per- 
centage of  ORGANIC  MATTER.    The  inorganic  residue  may 
then  be  digested  in  dilute  hydrochloric  acid,  and  retained 
for  subsequent  examination  (706). 

703.  Treatment  of  the  second  portion. — A  second  portion 
of  the  crushed  or  rasped  bone,  weighing  one  hundred 
grains,  is  to  be  digested  for  a  day  or  two,  in  cold  dilute 
hydrochloric  acid,  containing  one  part  of  the  strong  acid 
to  five  or  six  of  water;  the  whole  being  kept  at  a  tem- 
perature not  higher  than  about  50°,  as  otherwise  some 
traces  of  the  animal  matter  of  the  bone  would  be  acted 
upon  by  the  acid.     The  whole,  or  at  least  by  far  the 
greater  portion  of  the  inorganic  matter  is  thus  dissolved, 
and  when  the  acid  liquid  has  been  well  washed  out  of 
the  insoluble  residue  by  means  of  cold  water,  little  will 
remain  but  the  cartilaginous  matter  of  the  bone. 

704.  The  cartilaginous  residue  is  to  be  dried  on  a 
water-bath,  and  then  boiled  with  a  little  ether,  which 
must  be  poured  off,  and  renewed,  if  necessary,  until  all 
the  fat  is  dissolved.    The  ethereal  solution  is  then  evapo- 
rated to  dryness  in  a  counterpoised  capsule  on  a  water- 

22* 


258  QUANTITATIVE    ANALYSIS    OF    BONE. 

bath;  when  the  weight  of  residue  will  give  the  percent- 
age of  FAT  in  the  bone. 

705.  The  matter  which  proved  insoluble  in  the  ether 
(70-i),  consisting  chiefly  of  cartilage,  with  traces  of  inor- 
ganic matter,  is  now  to  be  dried  on  a  chloride-of-calcium 
bath,  at  a  temperature  of  about  250°,  weighed  and  in- 
cinerated.    The  difference  between  the  weight  of  the  dry 
residue  before  and  after  incineration,  will  then  represent 
the  percentage  of  CARTILAGE  in  the  bone. 

706.  The  ash  left  after  the  incineration  of  the  first 
hundred  grains  of  bone  (702),  is  now  to  be  dissolved  in 
moderately  dilute  hydrochloric  acid;  a  gentle  heat  being 
applied  if  necessary.     The  acid  solution  is  then  slightly 
supersaturated  with  ammonia,  which  will  throw  down  the 
phosphate  of  lime,  together  with  the  small  quantity  of 
phosphate  of  magnesia  and  fluoride  of  calcium ;  as  well 
as  any  traces  of  peroxide  of  iron  and  oxide  of  manganese 
that  may  be  present.    The  precipitate  is  to  be  well  washed, 
filtered,  dried,  and  ignited ;  after  which  its  weight  will 
represent  the  amount  of  BONE  EARTH,  consisting  of  PHOS- 
PHATE   OF    LIME    with    PHOSPHATE    OF    MAGNESIA,    and 
FLUORIDE  OF  CALCIUM,  in  one  hundred  parts  of  the  bone. 

707.  If  it  is  required  to  determine  separately  the  pro- 
portion of  phosphate  of  magnesia,  the  ignited  precipitate 
(706),  after  being  weighed,  is  to  be  redissolved  in  dilute 
hydrochloric  acid;  the  acid  solution  is  then  mixed  with 
an  excess  of  perchloride  of  iron  (Fe2Gl^  and  supersatu- 
rated with  ammonia.     The  phosphoric  acid  of  the  earthy 
phosphates  is  thus  precipitated  in  combination  with  per- 
oxide of  iron,  together  with  any  excess  of  uncombined 
peroxide  of  iron,  leaving  in  solution  the  chlorides  of 
calcium  and  magnesium.*    The  lime  (chloride  of  calcium) 
is  first  precipitated  by  adding  oxalate  of  ammonia  (NH4 
0,C203)  as  long  as  it  causes  a  precipitate,  boiling  the 
mixture,  and  filtering.     The  filtered   solution   is   then 
concentrated  by  evaporation,  and  the  magnesia  thrown 
down  by  adding  phosphate  of  soda  (2NaO,HO,PO<)  and 
a  decided  excess  of  ammonia.     The  mixture  is  allowed 
to  stand  for  some  hours,  after  which  the  precipitated 

*  The  process  described  in  paragraphs  68-71  will  give  more  exact 
results. 


QUANTITATIVE    ANALYSIS    OF    BONE.          259 

double  phosphate  of  ammonia  and  magnesia  (2MgO,NI I, 
O,PO5+12Aq)  is  to  be  filtered,  dried,  and  ignited,  by 
which  it  is  converted  into  phosphate  of  magnesia  (42Mg 
O,PO5),  and  weighed.  This  weight  will  represent  the 
amount  of  PHOSPHATE  OF  MAGNESIA  in  the  100  grains  of 
bone;  whichr  when  deducted  from  the  whole  earthy 
phosphates  (706),  will  give  the  percentage  of  PHOSPHATE 
OF  LIME. 

707 a.  General  method  of  determining  phosphoric  acid. — 
Since  phosphoric  acid  is  a  constant  component  of  the 
inorganic  part  of  the  solids  and  fluids  of  the  body,  it  is 
necessary  to  be  able  to  determine  it  directly  in  all  cases. 
The  opportunity  may  be  taken  of  applying  the  following 
process  (Chancel)  to  the  determination  of  phosphoric  acid 
in  bone.  Ten  grains  of  the  bone-ash  are  dissolved  in 
nitric  acid,  with  the  aid  of  heat.  The  solution  is  diluted 
and  a  little  nitrate  of  baryta  added,  to  remove  sulphuric 
acid;  nitrate  of  silver  is  then  added,  without  previous 
filtration,  to  precipitate  the  chlorine.  The  filtered  solu- 
tion is  treated  with  sulphuretted  hydrogen,  and  the 
liquid  filtered  from  the  sulphide  of  silver  is  heated  until 
no  more  sulphuretted  hydrogen  is  perceptible.  A  solu- 
tion of  nitrate  of  bismuth  (Bi03,3NO5)  is  then  added,  and 
the  precipitate  of  phosphate  of  bismuth  (BiO3PO5)  is 
collected  upon:  a  filter,  washed  with  boiling  water,  ig- 
nited in  a  porcelain  crucible  (the  filter  being  burnt  sepa- 
rately) and  weighed.  The  following  proportion  then 
gives  the  phosphoric  acid : — 


305  :         71  :  :     Weight  of  precipitate     :    x 

708.  The  solution  filtered  from  the  precipitate  of 
earthy  phosphates  (706),  containing  the  portion  of  lime 
which  existed  in  the  bone  as  carbonate,  is  now  to  be 
treated  with  oxalate  of  ammonia  as  long  as  any  precipi- 
tate is  produced.  The  whole  of  the  lime  is  thus  separated 
as  oxalate  (CaO,C203-f2Aq),  which,  after  boiling  the  mix- 
ture, is  filtered,  dried,  and  ignited.*  The  oxalate  is  c^- 

*  See  paragraph  69. 


260          QUANTITATIVE    ANALYSIS    OF    BONE. 

verted,  during  the  ignition,  into  carbonate  (CaO,C02),  so 
that  the  weight  of  the  ignited  precipitate  will  represent 
the  amount  of  CARBONATE  OF  LIME  in  the  hundred  grains 
of  bone. 

709.  As  a  check  upon  the  estimation  of  the  carbonate 
of  lime,  the  amount  of  carbonic  acid  in  the  bone  may  be 

determined  by  placing  100  grains  of  the 
Fig.  75.  unburnt  bone  in  fine  powder,  in  a  flask 
a,  provided  with  a  desiccating  tube  &, 
containing  fragments  of  chloride  of  cal- 
cium (Fig.  75).  A  test-tube  (c)  contain- 
ing hydrochloric  acid  is  then  placed  in 
the  flask,  and  the  whole  apparatus  is 
weighed ;  after  which  the  acid  is  allowed 
to  flow  gradually  upon  the  powder,  from 
which  it  will  expel  the  CARBONIC  ACID. 
The  amount  of  the  latter  which,  being  gaseous,  escapes 
in  a  dry  state  through  the  chloride  of  calcium  tube  d,  is 
then  represented  by  the  loss  of  weight  which  the  appa- 
ratus with  its  contents  experiences  during  the  experi- 
ment (337).  It  will  probably  be  found  that  the  carbonic 
acid  thus  determined,  bears  to  the  carbonate  of  lime 
(708)  the  proportion  of  22  to  50,  those  being  the  atomic 
weights  of  carbonic  acid  and  carbonate  of  lime  respect- 
ively.* 

710.  The  solution  filtered  from  the  oxalate  of  lime 
(708),  which  contains  the  soluble  salts  (chiefly  chloride 
of  sodium),  together  with  the  excess  of  oxalate  of  am- 
monia employed  to  precipitate  the  lime,  is  now  to  be 
evaporated  to  dryness,  and  the  residue  ignited  in  order 
to  expel  the  ammoniacal  salts.     The  weight  of  the  resi- 
due, after  ignition,  will  then  represent  the  percentage  of 

SOLUBLE  SALINE  MATTER. 

711.  The  following  analyses  will  serve  to  illustrate  the 
percentage  composition  of  bone  both  of  man  and  some  of 
the  lower  animals. 

*  To  obtain  an  exact  result  by  this  process,  the  flask  should  be 
-'irnished  with  a  narrow  tube  e,  dipping  into  the  liquid,  kept  closed 
dun*.-?  the  evolution  of  gas  ;  at  the  conclusion  of  the  experiment  the 
tube  sho.\d  v>e  opened  and  air  slowly  sucked  through  the  drying-tube 
b  as  long  as  -aie  weight  of  the  apparatus  diminishes. 


QUANTITATIVE   ANALYSIS    OF    BONE. 


261 


Analysis  I.    (Von  Bibra.) 
Showing  the  Composition  of  the  Bones  of  a  Child  two  months  old. 


Tibia. 
Phosphate  of  lime,  with  a  little  fluoride  )       57.54 

Ulna. 

Kfi.OK 

of  calcium          j 

«'    '    •  »  •  J 

Carbonate  of  lime  6-02 

6-07 

Phosphate  of  magnesia  .         .         .         .           1-03 

1-00 

Soluble  salts          .....            0-73 

1-65 

Cartilage*     ......          33-86 

34-92 

Fat        0-82 

1-01 

Analysis  11.    (Von  Bibra.) 

Composition  of  the  Bones  of  a  Middle-aged  Man. 

Femur.               Tibia.        Humerus. 

Costa. 

Phosphate    of    lime  ) 

with  a  little  fluo-  \   59-63            58-95        59-87 

55-66 

ride  of  calcium,      j 

Carbonate  of  lime        .     7-33             7-08          7-76 

6-64 

Phosphate  of  magnesia    1-32              1-30          1-09 

1-07 

Soluble  salts        .         .     0-69              0-70          0-72 

0-62 

Cartilage     .         .         .  29-70            30-42        29-28 

33-97 

Fat      ....     1-33              1-55          1-28 

2-04 

Analysis  III.     (Berzehus.) 

Composition  of  Human  Bone. 

51-04 

2-00 

11-30 

1-16 

Soda,  with  a  little  chloride  of  sodium    .         . 

1-20 

Cartilage         

32-17 

1-13 

Analysis  IV.     (Von  Bibra.) 

Composition  of  the  Bones  of  the  Lower  Animals. 

Femur  of           Femur  of       Femur  of 

Humerns  of 

sheep  aged         bull  aged      horse  aged 

cat  aged 

4  years.            4  years.           6  years. 
Phosphate  of  lime  \ 

6  years. 

with  a  little  fluo-  [•         55-94             54-07          54-37 
ride  of  calcium  .  J 

59-30 

Carbonate  of  lime  .             12-18              10-71           12-00 

10-69 

Phosphate  of  mag-  )             ,  ™                1-42            i  .oq 

1-70 

nesia           .         .  ) 

Soluble  salts  .         .               0-50               0-80            0-70 

0-40 

Cartilage        .         .              29-68             29-09          27-99 

27-21 

Fat        ...                0-70               1-91            3-11 

0-70 

*  According  to  Fremy,  the  percentage  composition  of  this  portion  of 
bone  is 

Carbon 49-21 

Hydrogen    .         .         .         .         .  6-50 

Nitrogen 17-86 

Oxygen 25-14 


262 


MORBID    BONE. 


Vertebrae 


of  dolphin. 

Phosphate   of  lime  ") 
with  a  little  fluo-  [• 
ride  of  calcium  .  J 

52-51 

Carbonate  of  lime  . 

9-37 

Phosphate  of  mag-  ) 
nesia           .         .  ) 

0-98 

Soluble  salts  . 

1-24 

Cartilage 

33-97 

Fat 

Humerus       Vertebrae      Vertebrae 
of  thrush.       of  snake,      of  salmon. 


62-65 

6-05 
0-90 

0-84 

28-02 

1-54 


59-41 

7-82 
1-00 

0-73 

24-93 

6-11 


36-64 

1-01 
0-70 

0-83 
21-80 

38-82 


SECTION  III. 
Morbid  Bone. 

712.  Certain  diseases  are  found  to  be  always  accom- 
panied by  remarkable  changes  in  the  chemical  composi- 
tion of  the  bones;  the  earthy  matters  being  sometimes 
so  deficient,  that  they  no  longer  possess  the  rigidity  and 
strength  necessary  for  sustaining  the  weight  of  the  body. 
Other  variations  also  are  occasionally  met  with,  a  few 
examples  of  which  are  subjoined,  the  composition  being 
calculated  upon  100  parts. 

Analyses  of  the  Tibiae  of  three  Rachitic  Children.     (Lehmann.) 


Phosphate  of  lime 

Carbonate  of  lime   . 

Phosphate  of  magnesia 

Chloride  of  sodium . 

Soda 

Cartilage 

Fat 


I. 

II. 

III. 

32-04 

26-94 

28-13 

4-01 

4-88 

3-75 

0-98 

0-81 

0-87 

0-21 

0-27 

0-28 

0-54 

0-81 

0-73 

54-14 

60-14 

58-77 

5-84 

6-22 

6-94 

Analyses  of  Bone  in  Osteomalacia.     (Prdsch.") 

Vertebra.  Costa. 

Phosphate  of  lime 13-25  33-66 

Carbonate  of  lime 5-95  4-60 

Sulphate  of  lime  and  phosphate  of  soda .         .          0-90  0-40 

Cartilage 74-64  49-77 

Fat 5-26  11-63 

Analyses  of  Carious  Bone.    (Valentin.) 


Phosphate  of  lime 
Carbonate  of  lime 
Phosphate  of  magnesia 
Chloride  of  sodium 
Carbonate  of  soda 
Organic  constituents     . 


Vertebrae  of  a 
man  aged  20. 

.  33-914 

.  7-602 

.  0-389 

.  3-157 

.  1-118 

,  54-830 


34-383 
6-636 
1-182 

1-919 

55-880 


EXAMINATION    OF    MIXED    ANIMAL    FLUIDS.      263 

Analysis  of  Necrotic  Done  of  a  Middle-aged  Man.    (  Von  Bibra.) 
Phosphate  of  lime  with  a  little  fluoride  of  calcium 


Carbonate  of  lime 
Phosphate  of  magnesia 
Soluble  salts 
Cartilage 
Fat 


72-63 
4-03 
1-93 
0-61 

19-58 
1-22 


CHAPTER  X. 

EXAMINATION  OF  MIXED  ANIMAL  FLUIDS. 

713.  ON  account  of  the  great  number  and  variety  of 
organic  substances  which  may  enter  into  the  composition 
of  such  a  mixture  as  we  are  now  considering,  it  is  alto- 
gether impossible  to  lay  down  any  general  and  consecu- 
tive scheme  of  experiments,  which  shall   comprise   all 
even  of  the  more  commonly  occurring  organic  compounds. 
All  that  I  shall  attempt,  therefore  in  the  present  chapter, 
is  to  describe  very  briefly  the  methods  of  detecting  the 
presence  of  a  few  of  the  substances  which  are  most  fre- 
quently met  within  organic  liquids,  and  which  are  of 
the  most  practical  importance  to  the  pathologist  and  the 
physician. 

714.  The  color,  consistence,  and  general  appearance  of 
the  fluid,  should  be  first  carefully  observed,  as  the   pre- 
sence  of  many  substances,  such  as   blood,  mucus,   fat, 
fibre,  &c.,  may  often  be  readily  detected,  even  with  the 
naked  eye.     Should  any  solid  or  semi-solid  matter  be 
held  in  suspension  in  the  liquid,  or  be  found  as  a  sedi- 
ment at  the  bottom,  it  should  be  separated,  either  by 
decantation,  or  by  filtering  through  fine  muslin  or  paper. 

715.  The  matters  thus  separated  from  the  fluid  may  be 
reserved  for  examination  under  the  microscope,  and  also, 
if  necessary,  with  othe*  tests.     The  following  substances, 
among  others,  may  in  this  way  be  readily  detected : — 
muscular  fibre  and  other  organized  tissues ;  epithelium 
(328) ;  mucus  and  pus  granules  (329) ;  fat  and  milk  glo- 
bules (325,  632,  633);  infusoria  of  several  kinds;  besides* 


264  FIBRIN — ALBUMEN  — CASEIN. 

various  amorphous  and  crystalline  substances,  many  of 
which  may  at  once  be  recognized  by  their  peculiar  form 
and  appearance  (315 — 332,  &c.). 

716.  The  liquid  may  first  be  tested  with  litmus  and 
turmeric  paper,  since  the  behavior  of  several  of  the  sub- 
stances  about  to  be  noticed,  with  reagents,  will  be  found 
to  vary  according  as  the  liquid  containing  them  is  acid, 
alkaline,  or  neutral. 

717.  The  specific  gravity  may  also  be  ascertained, 
when  it  can  conveniently  be  done,  as  a  knowledge  of  the 
density  of  the  fluid  will  serve  to  furnish  some  indication 
of  the  amount  of  solid  matter  held  in  solution  (276). 

Fibrin. 

718.  When  fibrin,  in  the  soluble  state,  is  contained  in 
a  liquid,  it  gradually  undergoes  spontaneous  coagulation, 
and  separates  from  the  solution,  forming  a  more  or  less 
firm  coagulurn  or  jelly :  and  if  other  matters  are  held  in 
suspension  in  the  liquid  previous  to  the  coagulation,  they 
are  usually  entangled  in  it — a  familiar  instance  of  which 
is  afforded  by  the  coagulation  of  blood  (473).     The  more 
important  peculiarities  of  fibrin  have  already  been  noticed 
in  paragraphs  472  to  481. 

Albumen. 

719.  When  albumen  is  suspected  to  be  present  in  so- 
lution, the  clear  liquid  is  to  be  gently  boiled  for  a  few 
minutes ;  if  coagulation  takes  place,  and  if  the  precipitate 
thus  occasioned  does  not  disappear  on  the  addition  of  a 
few  drops  of  nitric  acid,  albumen  is  present.     If  the  mix- 
ture is  alkaline,  it  should  be  neutralized  with  nitric  acid 
previous  to  boiling,  since  any  excess  of  alkali  would  tend 
to  retain  the  albumen  in  solution,  and  thus  prevent  the 
coagulation.     For   further   particulars   respecting  albu- 
men, and  its  behavior  with  reagents,  see  paragraphs  133, 
235,  466,  &c. 

Casein. 

720.  Casein  may  be  recognized  by  its  forming  a  white 
curdy  precipitate,  when  the  solution  containing  is  neu- 
tralized or  very  slightly  supersaturated  with  acetic  acid. 


PYIN — PUS— MUCUS.  265 

It  redissolves  however  if  the  acid  be  added  in  decided 
excess.  If  the  liquid  is  slightly  acid  to  test  paper,  casein 
hardly  need  be  looked  for,  since  it  is  not  soluble  in  acid 
solutions,  unless  the  acid  is  present  in  considerable  excess. 
It  may  be  distinguished  from  albumen  by  not  coagu- 
lating when  heated  ;  it  forms,  however,  a  thin  insoluble 
pellicle  on  the  surface  when  exposed  to  the  air  while  hot 
— of  which  a  familiar  example  is  afforded  in  the  skin  of 
boiled  milk.  If  casein  be  dissolved  in  acetic  or  any  other 
acid,  it  is  precipitated  on  the  addition  of  ferrocyanide  of 
potassium,  thus  resembling  the  other  modifications  of  pro- 
tein (625). 

Pyin. 

721.  This  substance,  which  appears  to  be  identical  with 
the  so-called  tritoxide  of  protein,*  and  is  consequently 
closely  allied  to  the  other  protein  compounds  (472),  may 
be  recognized  by  its  throwing  down  a  precipitate  with 
acetic  acid,  which  does  not  redissolve  in  an  excess  of  the 
acid.     A  solution  of  alum  also  causes  a  white  precipitate, 
insoluble  in  excess;  in  which  respect  pyin  differs  from 
glutin  and  chondrin  (725,  726).     Unlike  most  of  the  pro- 
tein compounds,  it  is  not  precipitated  by  ferrocyanide  of 
potassium. 

Pus. 

722.  When  pyin  has  been  detected  in  a  liquid,  it  is 
not  improbable  that,  on  examination  with  the  microscope, 
the  peculiar  pus  granules  (678)  will  also  be  found  to  be 
present  since  pyin  is  one  of  the  characteristic  constituents 
of  the  fluid  portion  of  pus  (676).     The  principle  charac- 
ters of  this  substance,  together  with  the  modes  of  its  de- 
tection, have  been  already  described  in  paragraphs  153, 
247,  674,  &o. 

Mucus. 

723.  If  much  mucus  is  present,  it  gives  to  the  mixture 
a  more  or  less  tenacious  and  ropy  consistence,  which  is 
very  characteristic.     Under  the  microscope  the  peculiar 

*  This  name  was  conferred  by  Mulder  upon  the  soluble  substance 
obtained  by  boiling  any  of  the  protein  compounds  for  several  hours 
with  water. 

23 


266  GELATINE — CHONDRIN. 

mucus  corpuscles,  as  well  as  the  fragments  of  epithelium 
which  usually  accompany  them,  will  also  probably  be 
apparent  (Fig.  5);  and  these  in  conjunction  with  the 
ropiness  above  alluded  to,  are  generally  sufficient  evi- 
dence of  the  existence  of  mucus.  When  present  only 
in  minute  quantity,  and  especially  when  mixed  with  pus, 
it  is  often  extremely  difficult,  if  not  impossible,  to  iden- 
tify it  with  any  degree  of  certainty.  (See  also  paragraphs 
31,  99,  210,  660,  &c.). 

Gelatine;   Chondrin. 

724.  These  substances,  which  are  formed  by  boiling 
the  cartilaginous  tissues  in  water,  closely  resemble  each 
other  in  many  respects ;  and  their  hot  aqueous  solutions 
become  gelatinous  on  cooling.     Glue,  isinglass,  and  the 
several  varieties  of  gelatine,  met  with  in  commerce,  are 
all  modifications  of  these  principles.     Both  gelatine  and 
chondrin    are    immediately  precipitated,  even   in  very 
dilute  solutions,  by  a  solution  of  tannin.     They  are  not 
precipitated   by  ferrocyanide   of  potassium ;    in   which 
respect  they  differ  from  the  protein  compounds.     They 
are  thrown*  down  from  their  strong  solutions  by  alco- 
hol, in  the  form  of  a  white  tenacious  precipitate ;  and 
creasote  causes   their   solutions  to  become  turbid  and 
gelatinous. 

725.  Gelatine,  which  is  obtained  by  boiling  in  water 
for  some  hours  the  cartilage  of  bone,  the  tendons,  skin, 
&c.,  is  characterized   by  giving  with  acetic  acid  a  very 
slight  precipitate,  which  readily  redissolves  in  an  excess 
of  the  acid.     A  solution  of  alum  gives  with  gelatine  no 
precipitate;  or  if  a  slight  opalescence  is  occasioned,  it 
disappears  on  the  addition  of  a  further  quantity  of  the 
precipitant. 

726.  Chondrin,  on  the  other  hand,  which  is  formed  by 
boiling  in  water  any  of  the  permanent  cartilages,  as  those 
of  the  larynx,  ribs,  &c.,  is  immediately  precipitated  by 
acetic  acid,  and  an  excess  of  the  acid  does  not  redissolve 
it.      Alum,   too,   causes  a  precipitate,  which,  however, 
readily  dissolves  when  the  salt  is  added  in  excess.     The 
solubility  of  chondrin  in  a  solution  of  alum  serves  to  dis- 
tinguish it  from  pyin  (721). 


BLOOD — BILIARY    MATTER — UREA.  267 

Blood. 

727.  The  color  which  it  imparts  to  any  liquid  with 
which  it  is  mixed,  is  usually  almost  sufficient  evidence 
of  the  presence  of  blood,  unless  the  quantity  is  very 
small.     The  red  corpuscles  may  also,  in  most  cases,  be 
detected  under  the  microscope,  more  or  less  altered  in 
form  and  size  by  the  action  of  the  fluid  in  which  they 
float  (456,  583).     When  blood  is  present,  albumen  also 
will  be  found  dissolved  in  the  liquid,  unless  it  has  been 
previously  coagulated  by  heat  or  otherwise;  it  may  be 
detected  by  the  application  of  heat,  and  nitric  acid,  in 
the  manner  described  in  paragraphs  235,  236,  &c. 

Biliary  Matter. 

728.  Biliary  matter,  if  present   in   any  considerable 
quantity,  generally  communicates  a  more  or  less  decided 
brown  or  yellowish  color  to  the  liquid,  and  also  a  pecu- 
liar bitter  taste.     It  may  be  identified  by  means  of  Hel- 
ler's and  Pettenkofer's  tests,  described  in  paragraphs  149 
and  151.     If  these  fail  to  detect  it  in  the  fluid,  a  little  of 
the  latter  may  be  evaporated  nearly  to  dry  ness  on  a 
water-bath,  and  a  strong  aqueous  solution  of  the  residue 
tested  as  before. 

Urea. 

729.  This  substance  may  be  detected  in  organic  liquids 
in   the  following  manner:    The  portion  of  the  organic 
mixture  intended  for  the  examination,  is  evaporated  to 
dryness  at  a  gentle  heat  on  a  water-bath,  and  the  dry 
residue  treated  with  alcohol,  which  will  dissolve  out  any 
urea  that  may  be  present,  together,  probably,  with  some 
other  of  the  matters  with  which  it  is  associated.     The 
alcoholic  solution  is  then  evaporated  to  dryness,  and  the 
dry  extract  digested  with  a  very  small  quantity  of  mode- 
rately warm  water;  which  will  readily  dissolve  out  the 
urea.    The  aqueous  solution  thus  obtained  is  then  mixed, 
after  filtering,  with  pure  nitric  acid,  in  the  manner  de- 
scribed in  paragraph  16,  and  then  cooled  by  means  of  a 
freezing  mixture;  when,  if  urea  is  present,  delicate  crys- 
tals of  the  nitrate  (Fig.  2)  will  gradually  appear.*    When 

*  Urea  may  be  detected  in  this  manner  in  blood,  chyle,  and  lymph, 
as  well  as  in  urine. 


268  KREATINE— INOSITE. 

the  quality  of  urea  is  very  small,  the  microscope  may  be 
employed  to  detect  any  traces  of  the  crystalline  nitrate, 
and  some  other  precautions  must  be  observed,  which 
have  been  described  in  paragraphs  181,  184,  341,  &c. 

Kreatine. 

729a.  For  the  detection  of  kreatine  in  an  organic  mix- 
ture, the  solid  portion  should  be  divided  as  finely  as  pos- 
sible, the  whole  dried  upon  the  water  bath,  and  digested 
with  hot  alcohol.  The  alcoholic  solution  having  been 
pressed  out,  is  evaporated  to  dryness  on  the  water-bath, 
the  residue  treated  with  water,  the  solution  precipitated 
by  acetate  of  lead  (not  added  in  exess)  and  filtered.  The 
filtrate  is  saturated  with  sulphuretted  hydrogen,  to  pre- 
cipitate the  lead,  and  the  solution  separated  from  the 
sulphide  of  lead  is  evaporated  to  a  syrup  and  set  aside 
for  some  days,  when  kreatine  will  crystallize  out  and 
may  be  recognized  by  the  characters  described  above, 
especially  by  converting  it  into  kreatinine  and  obtaining 
the  crystalline  precipitate  with  chloride  of  zinc. 

Inosite. 

7295.  The  presence  of  inosite  may  be  ascertained  (in 
an  aqueous  infusion  of  bullock's  lung,  for  example),  by 
acidulating  with  acetic  acid,  coagulating  the  albumen  by 
heat,  and  precipitating  the  filtered  liquid  with  acetate  of 
lead.  The  filtrate  from  this  precipitate  is  mixed  with 
tribasic  acetate  of  lead,  which  will  throw  down  any  ino- 
site if  present.  The  precipitate  is  suspended  in  water, 
decomposed  by  sulphuretted  hydrogen,  the  liquid  filtered 
from  the  sulphide  of  lead,  evaporated  to  a  very  small 
bulk,  mixed  with  four  volumes  of  boiling  alcohol,  filtered 
if  necessary,  and  set  aside  for  twenty-four  hours.  If  no 
crystals  of  inosite  have  then  been  deposited,  ether  is 
added  by  degrees  until  a  permanent  rnilkiness  is  pro- 
duced on  agitation.  The  liquid  is  again  set  aside,  when 
inosite  will  crystallize  out,  and  may  be  identified  by  treat- 
ing it  with  ammonia  and  chloride  of  calcium,  and  slowly 
evaporating  to  dryness,  when  a  rose  color  will  be  pro- 
duced. 


CHOLESTERIN    AND    SEROLIN— MILK.          2G9 
Fat. 

730.  When  any  considerable  amount  of  fatty  matter 
is  present  in  an  aqueous  mixture,  it  may  be  readily  de- 
tected with  the  naked  eye,  and  still  more  delicately  under 
the  microscope,  by  the  appearance  of  oily  or  fatty  glo- 
bules floating  on  the  surface.    When,  however,  the  quan- 
tity is  very  small,  or,  owing  to  other  circumstances,  no 
appearance  of  fat  is  to  be  seen ;  a  little  of  the  mixture 
suspected  to  contain  it,  is  to  be  evaporated  nearly  to  dry- 
ness  on  a  water- bath,  and  the  residue  digested  with  a  lit- 
tle warm  ether,  which  will  readily  dissolve  any  traces  of 
fatty  matter  that  may  be  present.     On  evaporating  the 
ethereal  solution  on  a  water-bath,  the  oil  or  fat  will  be 
left  as  a  residue,  and  may  be  identified  by  its  possessing 
the  well-known  physical  characters  of  fatty  matters  (158). 

731.  The  saponifiable  fats  most  commonly  met  with  in 
animal   fluids  are,  oleine  (C114H104O12),  stearine  (C114H110 
O,2),  margarine  (C108H104O12),  and  butyrine.     The  degree 
of  hardness  or  of  oiliness,  and  the  temperature  to  which 
the  fatty  matter  requires  to  be  raised   before  it  melts, 
serve  to  furnish  some  indication  as  to  the  relative  amounts 
of  the  Solid  stearine  and  the  oily  oleine.     Butyrine  may 
generally  be  detected  by  the  peculiar  smell  which  it  gra- 
dually acquires,  resembling  that  of  rancid  butter. 

Cbolesterin  and  Serolin. 

732.  If  either  of  these   substances  are  present,  they 
will  have  been  dissolved  by  the  ether  (730),  together  with 
any  other  fatty  matters  that  may  be  contained  in  the 
liquid.     They  may  be  separated  from  the  other  fats  by 
digestion  with  a  solution  of  potash,  which  will  dissolve 
out  the  saponifiable  fats,  and  leave  the  cholesterin  and 
serolin  unaffected  (596).     These  may  be   distinguished 
from  each  other  by  their  different  fusing  points,  that  of 
cholesterin  being  293°,  while  that  of  serolin  is  as  low 
as  97°. 

Milk. 

733.  The  well-known  physical  characters  of  milk  are 
generally  sufficiently  apparent  to  lead  to  its  detection, 
unless  largely  diluted  with  other  matters.     When  any 

23* 


270  SUGAR — AMMONIA. 

doubt  exists  as  to  its  presence,  a  drop  of  the  liquid  may 
be  examined  under  the  microscope  for  the  milk  globules 
(632) ;  and  the  clear  liquid,  after  filtration,  may  be  tested 
with  acetic  acid  for  casein  (623) ;  the  existence  of  which, 
in  any  fluid)  is  strong  evidence  of  the  presence  of  milk. 
The  residue  left  by  evaporating  the  liquid  to  dry  ness, 
may  be  tested  for  fat  also,  by  digestion  with  warm  ether, 
and  evaporating  the  ethereal  solution  on  a  water-bath 
(730). 

sugar. 

734.  The  most  convenient  test  for  the  presence  of 
sugar  is  that  known  as  Trommer's,  which  has  already 
been  fully  described  in  paragraphs  122  to  124.     Mau- 
mene's  (125),  and  the  fermentation  test  (128),  may  also, 
in  many  cases,  be  employed  with  advantage  ;  and,  indeed, 
it  is  always  more  satisfactory  to  confirm  the  results  of 
Trommer's  experiment,  by  applying  also  the  fermenta- 
tion test ;  since  the  suboxide  of  copper  may  be  sometimes 
produced  by  certain  other  organic  substances,  even  when 
no  sugar  is  present.     If  the  sugar  is  present  only  in  very 
minute  quantity,  it  may  be  advisable  to  evaporate  the 
liquid  to  dryness  on  a  water-bath,  and  re-dissolve  the 
soluble  portion  of  the  residue,  including  the  sugar,  in  a 
small  quantity  of  hot  water,  in  the  manner  described  in 
the  process  for  detecting  sugar  in  the  blood  (606).     The 
strong   aqueous   solution    may    then    be   examined   by 
Trommer's,  Maumene's,  and  the  other  tests. 

735.  When  cane  sugar  is  suspected  to  be  present,  the 
solution  should  first  be  boiled  for  a  few  minutes  with 
dilute  sulphuric  acid  before  the  application  of  Trommer's 
test,  in  order  to  convert  it  into  grape  sugar;  since  the 
cane  variety  does  not  otherwise  produce  the  same  char- 
acteristic results. 

Ammonia. 

736.  This  substance,  which  is  so  constantly  to  be  met 
with  in  animal  fluids,  as  one  of  the  results  of  the  decom- 
position   of   nitrogenous   compounds,    may   be    readily 
detected,  even  when  present  in  very  small  quantities. 
A  portion  of  the  liquid  is  mixed  in  a  test  tube  with  a 
little  caustic  potash,  or,  still  better,  with  caustic  baryta 


URIC    (OR    LITH1C)   ACID.  271 

(note  to  38),  and  warmed.  The  ammonia,  if  present,  is 
thus  disengaged,  and  may  be  detected  by  the  smell,  or, 
still  more  delicately,  by  holding  at  the  mouth  of  the  tube 
a  glass  rod  moistened  with  dilute  hydrochloric  acid,  when 
white  fumes  of  chloride  of  ammonium  will  be  distinctly 
visible. 

737.  If  the  ammonia  is  present  only  in  minute  quan- 
tity, a  little  of  the  suspected  liquid  may  be  mixed  with 
a  few  drops  of  dilute  sulphuric  acid,  in  order  to  fix  the 
ammonia,   and  then  concentrated  by  evaporation    at  a 
gentle  heat  on  a  water  bath ;  the  concentrated  liquid  may 
then    be    supersaturated    with    potash    or    baryta,    and 
examined  in  the  manner  above  described. 

Uric  {or  Lithic)  Add. 

738.  When  an  organic  mixture  is  suspected  to  con- 
tain uric  acid,  it  may,  if  free  from  albuminous  matter,  be 
acidified  with  a  few  drops  of  hydrochloric   acid,   and 
allowed  to  stand  a  short  time.    The  uric  acid  will  gradu- 
ally separate  in  the  form  of  minute  crystals  (20),  which 
may  be  examined  under  the  microscope,  and  also  tested 
with  nitric  acid  and  ammonia,  in  the  manner  described 
in  paragraph  23.     If  any  albuminous  matter  is  mixed 
with  the  liquid,  the  latter  is  to  be  evaporated  to  dryness 
on  a  water-bath,  and  the  residue  digested  with  a  dilute 
solution  of  caustic  potash.    The  alkaline  solution  is  then 
supersaturated   with  a   decided  excess  of  hydrochloric 
acid,  which  will  throw  down  the  uric  acid  in  the  form  of 
a  crystalline  precipitate.    If  the  quantity  is  small,  a  drop 
of  the  liquid  may  be  mixed  with  the  acid  on  a  strip  of 
glass,  and  examined  for  the  characteristic  crystals  under 
the  microscope  (318). 

738a.  Another  process,  which  is  sometimes  more  con- 
venient than  the  above,  consists  in  mixing  the  solution 
with  acetate  of  lead  as  long  as  it  yields  a  fresh  precipi- 
tate, filtering,  and  adding  tribasic  acetate  of  lead.  On 
standing,  urate  of  lead  will  be  precipitated,  which  must 
be  washed,  suspended  in  water,  and  decomposed  by  sul- 
phuretted hydrogen.  The  solution  is  boiled,  filtered 
from  the  sulphide  of  lead,  and  evaporated  to  a  small 
bulk.  On  cooling,  crystals  of  uric  acid  are  deposited. 


272  SYSTEMATIC    EXAMINATION    OF 

739.  The  principal  characters  of  uric  acid,  and  the 
methods  of  detecting  and  estimating  it  in  the  urine,  have 
been  already  noticed  in  the  several  chapters  of  Part  I. 

Systematic  Examination  of  Mixed  Fluids  for  the  Proximate 
Constituents  of  Animal  Sodies. 

Some  of  the  proximate  constituents  of  the  solids  and 
fluids  of  the  body,  such  as  fibrine  and  gelatine,  are  recog- 
nizable by  their  characteristic  external  appearance,  but 
the  greater  number  give  no  indication  of  their  existence 
unless  specially  sought  for,  so  that  it  is  desirable  to  follow 
some  systematic  plan  of  examination  in  order  that  they 
may  not  be  overlooked.  The  solid  organs  must  be 
divided  as  minutely  as  possible,  and  digested  for  some 
time  in  tepid  water. 

The  reaction  of  the  liquid  to  test-papers  having  been 
recorded,  it  is  acidified,  if  necessary,  with  acetic  acid,  and 
heated  on  a  water-bath  in  order  to  coagulate  albumen, 
which  is  then  filtered  off.  On  allowing  the  hot  filtrate 
to  stand  for  some  time,  uric  acid  will  crystallize  out  as  it 
cools.  The  solution  is  then  very  nearly  neutralized  with 
potash,  and  acetate  of  lead  added,  to  precipitate  sulphuric 
and  phosphoric  acids,  as  well  as  coloring  and  extractive 
matters;  the  filtered  liquid  is  mixed  with  an  excess  of 
tribasic  acetate  ot  lead.  The  precipitate,  which  may  con- 
tain inosite,  is  decomposed  by  sulphuretted  hydrogen, 
and  the  solution  evaporated  till  a  portion  becomes  per- 
manently turbid  when  mixed  with  alcohol,  the  whole  is 
then  mixed  with  an  equal  volume  of  alcohol,  heated  till 
the  turbidity  disappears,  and  set  aside  for  a  day  or  two 
that  the  inosite  may  crystallize  out. 

The  filtrate  from  the  precipitate  produced  by  tribasic 
acetate  of  lead  is  now  mixed  with  a  slight  excess  of 
ammonia,  and  any  precipitate  is  collected,  decomposed 
by  sulphuretted  hydrogen,  and  the  solution,  after  eva- 
poration, examined  for  sugar. 

The  liquid  filtered  from  the  precipitate  produced  by 
ammonia  is  treated  with  sulphuretted  hydrogen,  filtered 
from  the  sulphide  of  lead,  evaporated  to  a  small  bulk 
upon  the  water-bath,  and  tested,  with  oxalic  acid  (14), 
for  urea. 


MIXED    FLUIDS.  273 

The  solution  is  then  evaporated  to  a  syrup,  and  mixed 
with  moderately  strong  alcohol  to  precipitate  the  oxalates 
of  the  alkalies.  The  alcohol  is  evaporated,  the  excess  of 
oxalic  acid  removed  by  the  careful  addition  of  lime-water, 
and  the  filtered  solution  evaporated  till  an  equal  volume 
of  absolute  alcohol  renders  it  permanently  turbid.  It  is 
then  mixed  with  alcohol  and  set  aside  for  a  day  or  two, 
when  taurine  will  be  deposited  in  crystals. 

The  alcoholic  solution  is  again  evaporated  on  the 
water-bath,  and  if  the  residue  is  much  colored,  it  may 
be  dissolved  in  a  little  water  and  boiled  with  hydrated 
oxide  of  lead,  the  filtered  solution  being  afterwards 
treated  with  hydrosulphuric  acid  to  remove  the  lead, 
and  evaporated  to  a  syrup.  On  allowing  this  to  stand 
for  some  time,  kreatine  and  leucine*  may  crystallize  out. 
They  may  be  washed  with  cold  absolute  alcohol,  and 
identified,  the  kreatine  by  its  convertibility  into  krea- 
tinine,  and  the  leucine  by  the  woolly  sublimate  which  it 
furnishes  when  heated  in  a  tube.  The  mother  liquor 
from  these  may  contain  Jcreatinine,  recognizable  by  its 
behavior  with  chloride  of  zinc. 

*  Leucine  (C12HI3N04)  and  tyrosine  (C,8H)IN06)  have  been  detected 
in  the  spleen,  pancreas,  and  liver,  and  the  former  also  in  the  lungs, 
and  both  have  been  observed  in  the  urine  in  disease.  Tyrosine  is 
identified  by  digesting  it  with  sulphuric  acid,  diluting  with  water, 
heating  the  solution  with  carbonate  of  lime,  filtering,  and  adding  per- 
chloride  of  iron,  which  produces  a  violet  color.  Protonitrate  of  mer- 
cury gives  a  red  precipitate  and  a  pink  liquid  when  added  to  a  solu- 
tion of  tyrosine. 


PART  V. 

V 

THE  DETECTION  OF  POISONS  IN  ORGANIC 
MIXTURES,  &c. 


CHAPTER  I. 

ARSENIC. 

IT  is  impossible  to  insist  too  strongly  on  the  necessity 
for  the  most  careful  examination  into  the  purity  of  all 
the  substances  employed  in  the  detection  of  poisons.  No 
evidence  with  respect  to  the  presence  of  a  poisonous 
substance  can  be  regarded  as  perfectly  conclusive,  unless 
the  reagents  employed  have  been  tested,  in  the  same 
quantities,  and  by  the  same  processes,  as  were  employed 
in  detecting  the  poison,  without  affording  any  indication 
of  its  presence. 

Moreover,  if  any  particular  substance,  though  not  a 
poison,  be  detected  in  the  course  of  the  examination, 
with  all  the  bearings  of  which  upon  the  tests  employed 
the  investigator  is  not  perfectly  familiar,  the  same  series 
of  operations  should  be  conducted  with  that  substance, 
to  ascertain  whether  it  might  lead  to  error. 

740.  Although  all,  or  nearly  all,  the  compounds  of 
arsenic  appear  to  be  more  or  less  intensely  poisonous,  I 
shall  here  allude  especially  to  the  detection  of  arsenious 
acid  (AsO3) ;  since  in  the  vast  majority  of  cases  in  which 
arsenic  is  taken,  whether  criminally  or  accidentally,  it  is 
in  the  form  of  arsenious  acid,  or,  as  it  is  often  called, 
oxide  of  arsenic,  or  white  arsenic.  The  experiments 
which  I  am  about  to  describe  will  serve,  however,  for  the 
most  part,  equally  well  for  identifying  the  presence  of 
arsenic  in  other  forms  of  combination  than  that  of  arseni- 


IDENTIFICATION    OF    ARSENIOUS    ACID.        275 

ous  acid;  so  that,  if  the  processes  are  carefully  conducted, 
the  risk  of  any  traces  of  the  metal  escaping  detection  is 
very  small. 

741.  When  the  presence  of  the  sulphide  (or  sulphuret) 
of  arsenic  (AsS3)  is  suspected,  the  substance  supposed  to 
contain  it  may  be  first  examined  for  any  particles  of 
yellow  powder;  which,  if  present,  should  be  mixed,  when 
dry,  with  a  little  black  flux,  or  with  a  mixture  of  dry 
carbonate  of  soda  and  charcoal,  and  heated  in  a  small 
German  glass  tube,  closed  at  one  end  ;  when,  if  it  consists 
of  sulphide  of  arsenic,  a  crust  of  the  metal  will  appear 
in  the  upper  part  of  the  tube  (743).    If  no  yellow  powder 
can  be  detected,  the  mass  in  which  it  is  suspected  to  be 
present  is  to  be  treated  according  to  the  directions  given 
hereafter. 

SECTION  I. 

Identification   of  Arsenious   Acid  when   unmixed  with   other 
substances. 

742.  Place  a  little  of  the  white  powder  in   a   small 
tube  of  German  glass,  closed  at  one  end,  and  heat  it 
gradually  in    the   flame    of    a 

spirit  lamp,  taking  care  to  warm  Fig.  76. 

the   upper    part    of    the   tube  *. 

slightly  before  heating  the  ar- 
senious  acid.  If  it  is  arsenious 
acid,  it  will  sublime,  and  con- 
dense in  the  upper  part  of  the 
tube,  forming  a  colorless  crys- 
talline  sublimate,  which,  when  b- 

examined  with  a  good  lens  or 
microscope,  will  be  found  to 
consist  of  beautiful  sparkling 
octohedral  crystals  (Fig.  76).  Arsenious  Acid. 

The  size  and  regularity  of  the 

crystals  appear  to  depend  on  the  slowness  with  which 
the  vapor  is  condensed.  If  the  surface  of  the  glass  on 
which  the  condensation  takes  place  is  quite  cold,  the 
sublimate  is  often  amorphous,  as  may  be  seen  by  holding 


276  AESENIC. 

a  piece  of  cold  glass  in  the  fumes  given  off  by  a  little 
arsenious  acid  heated  on  charcoal.* 

743.  Mix  a  little  of  the  suspected  powder  with  a  large 
proportion  of  black  flux,  or  of  carbonate  of  soda  and 

charcoal,  which  for    this    purpose    should 
Fig-  77.        be  perfectly  dry,  and  heat  the  mixture  in  a 
small  tube  of  German  glass  before  the  blow- 
pipe.    If  arsenic  is  present,  it  will  be  re- 
duced to  the  metallic  state,  and  sublime  into 
the  upper  part  of  the  tube,  forming  a  shining 
metallic  crust  (a,  Fig.  77).     The  part  of  the 
tube  which  contains  the  crust  may  then  be 
filed  off',  wrapped  in  a  piece  of  strong  paper 
and  broken,  the  fragments  of  the  crust  being 
placed  in  another  tube,  and  again  heated. 
The  reduced  metal  will  in  this  way  be  re- 
converted into  arsenious  acid,  crystals  of  which  will  con- 
dense in  the  cool  part  of  the  tube  (742). 

744.  Make  a  solution  of  some  of  the  powder  by  boiling 
it  for  some  minutes  with  water,  in  which  arsenious  acid 
is  sparingly  soluble,  and  apply  to  separate  portions  of 
the  solution  the  following  tests.     (See  also  745  and  749.) 

(a)  Acidify  a  portion  of  the  solution  with  a  drop  or 
two  of  hydrochloric  acid,  and  pass  a  current  of  hydro- 
sulphuric  acid  gas  (sulphuretted  hydrogen)  through  the 
liquid,  until  it  smells  distinctly  of  the  gas.     If  arsenious 
acid  is  present,  a  bright  yellow  precipitate  of  sulphide 
(AsS3)  will  be  thrown  down,  very  easily  dissolved  by 
ammonia. 

(b)  Add  to  a  second  portion  of  the  solution  a  few  drops 
of  ammonio-nitrate  (AgO,N06,%NH^  of  silver.    If  arseni- 
ous acid  is  present,  a  canary  colored  precipitate  of  arsenite 
of  silver  (3AgO,As03)  will  be  thrown  down,  which  is 
soluble  in  nitric  acid  and  also  in  ammonia. 

(c)  Test  a  little  of  the  solution  with  ammonio-sulphate 
(CuO,SO£NHyHO)  of   copper.     This  will   cause,  with 

*  For  much  valuable  information  with  respect  to  the  detection  of 
arsenious  acid  with  the  aid  of  the  microscope,  we  are  indebted  to  Dr. 
Guy's  minute  investigations,  an  abstract  of  which  is  given  in  his 
Principles  of  Forensic  Medicine,  2d  edition. 


MARSH  S    TEST. 


277 


Fig.  78. 


arseriious  acid,   a  pale-green  precipitate  of  arsenite  of 
copper  (2CuO,IIO,AsO3). 

MarsVs  Test. 

745.  Arrange  a  wide-mouthed  bottle,  of  six  or  eight 
ounces'  capacity,  with  tubes  as  shown  in  the  annexed 
figure ;  the  tube  d  being  of  hard  German  glass.     Place 
in  it  a  few  fragments  of  zinc,  and  add  a  little  dilute  sul- 
phuric acid,  consisting  of  one  part  of  the  strong  acid  to 
six     or     eight    of    water. 

When  the  hydrogen  has 
been  coming  oft'  about  five 
minutes,*  apply  a  light  to 
the  gas  as  it  issues  from 
the  aperture  at  e,  and  hold 
over  it,  or  rather  in  it,  a 
clean  porcelain  crucible 
lid,  in  order  to  prove 
whether  any  traces  of  ar- 
senic are  contained  in  the 
zinc  or  acid  employed,  in 
which  case  a  more  or  less 
distinct  arsenical  stain  would  be  produced.  If  the  ma- 
terials are  thus  found  to  be  pure,  a  little  of  the  solution 
of  the  supposed  arsenic  is  to  be  introduced  through  the 
tube  b. 

746.  Again  apply  a  light  to  the  jet  of  gas  at  e,   and 
hold  in  the  flame  a  clean  porcelain  crucible  lid.  If  arsenic 
is  present,  dark  spots  of  the  metal  will  be  deposited  on 
the  surface  of  the  porcelain,  wherever  it  has  been  allowed 
to  enter  the  flame.     A  few  of  these  stains  may  be  pre- 
pared and  tested  in  the  following  manner,  in  order  to 
prove  whether  they  really  consist  of  arsenic,  and  not  of 
antimony;  which  latter,  if  present,  would  produce  stains 
very  similar  in  appearance  to  those  of  arsenic. 

(a)  Apply  the  heat  of  a  spirit  lamp  to  one  of  the  spots. 

*  This  interval  must  be  allowed  to  elapse,  in  order  that  the  whole 
of  the  common  air  in  the  apparatus  may  be  expelled  before  the  light 
is  applied ;  since  a  mixture  of  hydrogen  and  common  air  is  highly 
explosive. 

24 


278 


ARSENIC. 


If  arsenic,  it  will  readily  volatilize,  and  a  slight  smell, 
resembling  garlic,  will  probably  be  perceptible. 

(b)  Moisten  one  of  the  spots  with  a  drop  of  yellow 
hydrosulphate    of    ammonia,    containing   an    excess    of 
sulphur.     If  it  consists  of  arsenic  it  will  remain  undis- 
solved  for  some  considerable  time;    while,   if    it  were 
antimony,  it  would  immediately  dissolve. 

(c)  Add  a  drop  or  two  of  a  solution  of  chloride  of  lime 
(CaOGl)  to  one  of  the  stains.     If  it  consists  of  arsenic  it 
will  immediately  dissolve. 

747.  Hold  over  the  flame  a  short  wide  test  tube  (Fig. 
79),  so  as  to  collect  the  fumes  of  arsenious  acid  formed 
during  the  combustion  of  the  arseniuretted  hydrogen. 
The  arsenical  sublimate  may  be  dissolved  in  hot  water, 
and  the  solution  tested  as  described  in  paragraph  744, 
a,  b,  and  c.  (See  also  749.)  The  sublimate  formed  in  the 

tube  by   antimony,   under 
Fig-  79.  the     same     circumstances, 

would,  on  the  contrary, 
prove  quite  insoluble  in 
water. 

748.  Apply  the  heat  of 
a  spirit  lamp  to  the  tube  at 
the  point  d  (Fig.  78),  and 
observe  the  formation  of  a 
dark  ring  of  metallic  ar- 
senic* inside  the  tube,  a 
little  in  advance  of  the 

heated  point.  The  arsenic  thus  deposited  may  be  vola- 
tilized backwards  and  forwards  in  the  tube,  by  applying 
the  heat  of  a  spirit  lamp  (765,  a).  If  the  tube  be  then 
disconnected  from  the  bottle,  and  the  arsenic  volatilized 
in  it  while  filled  with  atmospheric  air,  the  metal  will 
gradually  become  oxidized  and  converted  into  arsenious 
acid,  crystals  of  which  will  appear  in  the  cool  part  of  the 
tube. 

For  testing  very  small  quantities  of  a  substance  sus- 

*  In  consequence  of  a  secondary  decomposition  between  the  zinc 
and  sulphuric  acid  (Fordos  and  Gelis)  a  little  sulphuretted  hydrogen 
is  sometimes  formed,  which  gives  rise  to  a  yellow  ring  of  sulphide  of 
arsenic  by  the  side  of  the  metallic  ring. 


MARSH'S  TEST. 


279 


pected  to  contain  arsenic,  it  is  advisable  to  employ  a  much 
smaller  apparatus  (Fig  80)  than  that  above  described.  A 
two-ounce  bottle  may  be  used,  or  even  a  short  wide  test- 
tube  capable  of  containing  about  half  an  ounce  of  liquid. 
The  tube  through  which  the  gas  escapes  should  be  drawn 
out  at  the  extremity,  so  as  to  form  a  very  narrow  tubo 
about  two  inches  long.  In  such  cases  it  is  not  advisable 
to  run  the  risk  of  allowing  any  arsenic  to  escape,  on 
which  account  the  shoulder  of  the  tube  should  be  heated 

Fig.  80. 


with  a  spirit-lamp  before  the  suspected  solution  is  intro- 
duced, when  a  metallic  deposit  will  be  formed  in  the 
narrow  portion  of  the  tube  if  any  arsenic  be  present.  By 
employing  a  long  tube  constricted  at  intervals,  and  heat- 
ing each  of  the  wide  portions  of  the  tube,  several  metallic 
deposits  may  be  produced  at  the  same  time,  and  may  be 
made  the  subjects  of  various  confirmatory  experiments. 
When  a  very  small  apparatus  is  employed,  the  zinc  should 
be  free,  not  only  from  arsenic,  but  from  all  other  metals, 
so  that  the  evolution  of  hydrogen  may  be  slow  and 
uniform. 

If  Marsh's  apparatus  be  immersed  in  a  considerable 
volume  of  cold  water  whilst  in  use,  to  prevent  a  great 
rise  of  temperature,  it  is  not  necessary,  even  in  very 
minute  testing,  to  dry  the  gas,  as  is  sometimes  recom- 
mended. 

The  metallic  crusts  obtained  in  the  tube  should  be 
examined  by  the  following  confirmatory  tests. 


280  ARSENIC. 

(a)  Place  the  piece  of  tube  with  the  deposit  in  a  small 
hard  glass  tube,  and  apply  the  heat  of  a  spirit-lamp  ;  the 
crust  will  gradually  disappear,  and  crystals  of  arsenious 
acid  (742)  will  be  deposited  on  the  cooler  part  of  the  tube. 

(b)  Place  the  tube  and  deposit  in  a  little  water  con- 
tained in  a  small  test-tube,  and  add  two  or  three  drops  of 
yellow  sulphide  of  ammonium  ;  an  arsenical  crust  should 
not  dissolve  even  on  shaking  for  some  little  time.     Pour 
off  the  liquid,  wash  the  tube  several  times  with  distilled 
water,  and  add  some  clear  solution  of  chloride  of  lime 
(bleaching  powder),  by  which  the  crust  should  be  dissolved 
on  agitation. 

(c)  Boil  the  tube  containing  the  metallic  deposit  in  a 
few  drops  of  pure  nitric  acid,  in  a  small  test  tube;    when 
the  crust  is  dissolved,  rinse  the  solution  into  a  very  small 
porcelain  dish,  and  evaporate  just  to  dry  ness  over  the 
lamp.     The  residue  of  arsenic  acid  (As05)  which  should 
be  left,  would  become  moist  on  exposure  to  the  air  for  a 
few   minutes,  would  dissolve  easily  in    water,  and   the 
solution  would  give  a  brown-red  precipitate  of  arseniate 
of  silver   (3AgO,As05)  on  adding  nitrate  or  ammonio- 
nitrate  of  silver.      Should   no  precipitate  be   obtained, 
perhaps  a  little  free'  nitric  acid  may  have  been  left,  in 
which  case,  a  glass  rod  dipped  in  dilute  ammonia  will 
produce  the  precipitate. 

Rtinscti's  Test. 

749.  Before  applying  this  test,  the  simplest  by  which 
minute  quantities  of  arsenic  can  be  detected,  great  care  is 
required  to  insure  the  absence  of  that  metal  in  the 
hydrochloric  acid  and  the  copper  necessary  for  its  execu- 
tion. As  it  is  not  easy  to  procure  ordinary  copper  not 
containing  a  little  arsenic,  it  is  better  to  employ  the  metal 
deposited  by  the  electrotype  process  from  a  solution  of 
sulphate  of  copper  which  has  been  carefully  purified  by 
re  crystallization.  In  order  to  test  the  copper  and  hydro- 
chloric acid  for  arsenic,  the  following  experiments  should 
be  made. 

(1)  Mix  one  ounce  of  the  hydrochloric  acid  with  four 
ounces  of  water,  boil  it  in  a  small  flask  and  introduce  a 
small  strip  of  the  copper ;  boil  for  fifteen  or  twenty 


REINSCn's    TEST.  281 

minutes,  and  if  the  copper  remain  perfectly  bright,  the 
hydrochloric  acid  may  be  deemed  sufficiently  pure. 

(2)  Cut  a  square  inch  of  the  copper  into  small  strips 
and  heat  them  in  a  small  tube  of  hard  glass,  first  with 
the  flame,  and  afterwards  with  the  blowpipe,  to  see  if  any 
crystals,  of  arsenious  acid  are  deposited. 

(3)  Cut  two  square  inches  of  the  copper   into  strips, 
place  them    in  a  shallow   dish,  moisten  them  with  the 
hydrochloric  acid,  and  leave  them  for  some  time  exposed 
to  the  air;  add  a  little  more  hydrochloric  acid  from  time 
to  time,  until  all  the  copper  is  dissolved  (which    will 
require  many  hours'  exposure);   pour  the  solution  into  a 
small  retort,  add  about  half  its  bulk  of  hydrochloric  acid, 
and  distil  over  about  two  thirds  at  a  moderate  heat,  con- 
densing the  vapors  by  passing  them  through  a  tube  kept 
cool  by  wet  filtering-paper.     Dilute  the  distilled  liquid 
with  four  times  its  bulk  of  water,  and  boil  it  with  a  strip 
of  copper,  which  should  remain  untarnished  if  no  arsenic 
be  present. 

In  this  test  the  arsenical  copper  is  converted  into  sub- 
chloride  of  copper,  by  favor  of  the  oxygen  of  the  air, 


s  a  . 

The  arsenic  passes  into  solution  as  terchloride  (AsCl3) 
together  with  the  subchloride  of  copper  which  is  soluble 
in  hydrochloric  acid.  On  distilling,  the  terchloride  of 
arsenic  passes  over  with  the  acid. 

The  hydrochloric  acid  employed  in  Reinsch's  test  should 
also  be  free  from  sulphurous  acid,  which  may  be  detected 
by  dissolving  a  little  zinc  in  the  dilute  acid,  and  con- 
ducting the  gas  into  solution  of  acetate  of  lead  in  which 
a  black  precipitate  of  sulphide  of  lead  (PbS)  would  be 
produced  if  any  sulphurous  acid  were  present. 

In  order  to  apply  this  test,  acidify  a  little  of  the  aque- 
ous solution  of  the  substance  suspected  to  contain  arsenic, 
with  a  few  drops  of  pure  hydrochloric  acid,  and  boil  in 
it  two  or  three  strips  of  clean  copper  foil.  If  arsenic  is 
present,  it  will  be  deposited  in  the  metallic  state*  on  the 

*  Lippert  has  shown  that  this  deposit  is  not  pure  metallic  arsenic, 
but  an  alloy  containing  32  per  cent,  of  arsenic  and  68  of  copper 
(Cu5As). 


232  AKSENIC. 

surface  of  the  copper,  and  may  be  proved  to  be  arsenic 
in  the  following  manner: — 

(a)  Wash  the  copper  strips,  and  dry  them  by  gentle 
pressure  between  folds  of  filtering-paper,  or  by  warming 
them  on  a  water-bath ;  when  dry,  place  them  in  a  small 
clean  and  dry  tube  of  German  glass,  closed  at  one  end, 
and  apply  heat,  first  with  the  flame  alone,  and  afterwards 
with  the   blowpipe.      The  arsenic  will  volatilize;    and 
becoming  oxidized  while  in  contact  with  the  air,  arsenious 
acid  will  condense  in  the  upper  part  of  the  tube,  forming 
a  crystalline  sublimate,  which  may  be  examined  with  a 
lens  (742). 

(b)  Dissolve  the  sublimate  obtained  in  a  in  a  little  hot 
water,  and  apply  to  the  solution  the  tests  described .  in 
paragraph  744.    If  it  be  very  minute,  it  may  be  dissolved 
by  boiling  with  a  few  drops  of  nitric  acid,  and  tested  as 
in  748c* 

SECTION  II. 
Detection  of  Arsenic  in  the  presence  of  Organic  Matter. 

750.  The  cases  in  which  arsenic  has  to  be  detected  in 
the   presence  of  organic  matter  may  be  classed  under 
three  heads,  the  first  including  pretty  clear  and  homoge- 
neous liquids,  such  as  beer,  milk,  and  urine ;  the  second, 
such  thick  heterogeneous    mixtures  as  gruel,  pudding, 
and  the  contents  of  the  stomach  and  intestines ;  and  the 
third  the  solid  organs  of  the  body,  such  as  the  liver,  in 
which  arsenic  is  generally  to  be  detected  after  death  by 
poisoning. 

Detection  of  Arsenic  in  Organic  Liquids  which  are  pretty  clear 
and  homogeneous. 

751.  When  the  investigation  has  any  judicial  interest, 
the  quantity  of  the  liquid  should  be  carefully  recorded, 
and  every  portion  which  is  taken  for  a  separate  experi- 
ment must  be  measured,  so  that,  if  the  poison  be  detected, 
the  analyst  may  be  able  to  give  an  opinion  respecting  its 
quantity. 

*  Arsenic  is  much  more  difficult  to  detect  by  Reinscli's  test  when 
in  the  state  of  arsenic  acid.  It  then  requires  long  boiling  with  copper 
in  the  presence  of  a  very  large  excess  of  hydrochloric  acid. 


ARSENIC   IN    ORGANIC    MATTER.  283 

A  portion  of  the  liquid  may  then  be  acidified  with  a 
little  pure  hydrochloric  acid  (the  purity  of  which  has 
been  previously  ascertained),- and  then  boiled  with  two 
or  three  small  strips  of  tested  copper  foil.  If  arsenic  is 
present,  it  will  probably  be  deposited,  in  the  course  of  a 
few  minutes,  upon  the  surface  of  the  copper,  and  must 
be  treated  in  the  manner  presently  to  be  described.  It 
must  not,  however,  be  considered  certain  that  no  arsenic 
is  contained  in  the  liquid  until  after  boiling  the  mixture 
for  half  an  hour,  or  even  longer,  when,  if  no  stain  is 
produced,  which,  on  examination,  gives  indication  of 
arsenic,  it  may  safely  be  concluded  that  no  trace  of  the 
metal  is  present. 

It  occasionally  happens  that  a  little  fatty  animal  matter 
is  deposited  on  the  surface  of  the  copper  during  the 
boiling.  When  this  is  the  case,  the  copper  should  be 
boiled  with  a  little  ether  or  alcohol,  in  order  to  dissolve 
it,  before  being  exposed  to  heat  in  the  tube. 

752.  The  copper  strips  must  now  be  heated  in  a  small 
clean  and  dry  tube,  closed  at  one   end ;   when,  if  any 
arsenic  has  been  deposited  upon  them,  a  crystalline  sub- 
limate of  arsenious  acid  will  appear  in  the  upper  part  of 
the  tube.     If,  on  examination  with  a  lens,  the  sublimate 
is  found  to  exhibit  the  characteristic  crystalline  form  and 
appearance  of  arsenious  acid  (742),  there  can  scarcely  be 
a  doubt  of  the  existence  of  arsenic.     Proceed  further  as 
in  749  (b). 

753.  In  most  cases,  when  no  arsenic  has   been  thus 
reduced    upon  the  copper,  it  may  be  inferred   that  no 
appreciable  amount  of  that  metal  is  present,  but  should 
arsenic  be  detected,  the  analyst  should,  if  possible,  pro- 
ceed to  obtain  further  evidence  of  its  presence  by  other 
methods. 

If  the  liquid  be  not  very  viscid  and  liable  to  froth,  it 
may  be  acidulated  with  a  little  pure  sulphuric  acid,  fil- 
tered, if  necessary,  and  subjected  to  Marsh'-s  test  (745). 
If  frothing  should  take  place  to  any  inconvenient  extent, 
a  drachm  or  two  of  alcohol  may  be  poured  down  the 
funnel-tube  in  order  to  arrest  it. 

In  the  case  of  viscid  liquids  to  which  Marsh's  test  can- 
not be  applied,  it  is  recommended  to  evaporate  them  to 


284 


ARSENIC. 


Fig.  81. 


a  small  bulk  upon  a  water  bath,  to  acidify  strongly  with 
pure  hydrochloric  acid,  and  to  add  chlorate  of  potash,  in 
small  quantities,  until  the  liquid  becomes  so  limpid  as  to 
admit  of  filtration.  The  heat  of  the  water  bath  is  con- 
tinued until  the  smell  of  chlorine  has  in  great  measure 
disappeared,  and  the  liquid,  if  necessary,  filtered.  The 
clear  filtrate  may  be  tested,  either  by  Marsh's  process 
(745),  or  by  electrolysis. 

Electrolytic  test  for  Arsenic. — This  test  depends  upon 
the  circumstance  that  when  a  pretty  powerful  galvanic 
current  is  made  to  traverse  an  acid  liquid  containing 
arsenic,  arseniuretted  hydrogen  is  evolved  at  the  nega- 
tive terminal,  together  with  the  hydrogen  of  the  decom- 
posed water. 

To  construct  the  apparatus  (Fig.  81)  for  this  test,  a  two 

ounce  bottle,  with  a  mo- 
derately wide  mouth, 
is  selected,  and  a  file- 
mark  made  at  a  little 
distance  from  the  bot- 
tom, so  that  it  may  be 
extended  into  a  crack 
by  placing  a  red-hot 
wire  against  it,  and  led 
round  the  bottle  so  as 
to  cut  off  the  bottom. 
The  edges  having  been 
smoothed  with  a  file,  or 
by  grinding  on  a  wet 
stone,  a  pretty  deep 
groove  is  filed  round 
the  bottle  at  about  half 
an  inch  from  the  edge. 
A  piece  of  wet  parch- 
ment paper  *  is  doubled  down  over  the  bottom  of  the 
bottle,  and  secured  by  a  piece  of  stout  platinum  wire,  for 
which  the  groove  has  been  cut  in  the  glass.  A  perfo- 

*  Parchment-paper  is  now  commonly  sold.  It  may  be  made  by 
immersing  white  blotting-paper  for  an  instant  in  a  cold  mixture  of  the 
strongest  oil  of  vitriol  with  half  its  volume  of  water,  and  rapidly  wash- 
ing. 


ELECTROLYTIC    TEST    FOR    ARSENIC.  285 

rated  cork  is  inserted  in  the  mouth  of  the  bottle,  provided 
with  a  narrow  funnel  tube,  somewhat  drawn  out  at  the 
extremity,  which  should  nearly  touch  the  paper  dia- 
phragm, and  with  a  small  tube  bent  at  right  angles,  for 
the  exit. of  the  gas.  A  strip  of  platinum  foil  cut  into 
the  shape  of  a  spade  is  secured  between  the  cork  and  the 
neck  of  the  bottle,  so  that  its  broad  end,  hanging  down 
within  the  bottle,  may  nearly  touch  the  diaphragm,  the 
other  end  projecting  an  inch  or  two  beyond  the  neck  of 
the  bottle.  The  narrow  part  of  this  strip  may  be  about 
a  quarter  of  an  inch  wide,  and  the  broader  part  an  inch 
square.  The  bottle  is  placed  in  a  cylindrical  jar  not 
much  wider  than  itself,  and  not  so  flat  at  the  bottom  as 
perfectly  to  close  the  bottom  of  the  bottle ;  between  the 
side  of  the  jar  and  the  bottle,  a  second  strip  of  platinum 
foil,  similar  to  the  above,  is  suspended,  so  as  nearly  to 
touch  the  bottom  of  the  jar.  With  the  bent  tube  pro- 
vided for  the  egress  of  gas  there  is  connected,  by  means 
of  a  small  caoutchouc  tube,  a  rather  thick  narrow  tube, 
of  very  infusible  glass,  drawn  out  to  a  very  narrow  point, 
about  two  inches  long;  this  tube  must  be  supported 
across  the  ring  of  a  retort  stand. 

The  apparatus  is  charged  with  a  mixture  of  two 
drachms  of  pure  sulphuric  acid,  and  six  drachms  of 
water,  half  of  the  mixture  being  poured  down  the  funnel, 
and  the  remainder  into  the  outer  jar.  The  latter  is  then 
immersed  in  a  basin  of  water  to  prevent  too  great  a  rise 
of  temperature,  and  the  two  strips  of  platinum  are  con- 
nected with  the  terminal  wires  of  a  galvanic  battery,* 
the  wire  proceeding  from  the  zinc  extremity  being  united 
to  the  strip  within  the  bottle,  and  that  from  the  platinum, 
copper,  or  carbon  end  with  the  strip  which  dips  into  the 
outer  jar.  Tenor  fifteen  minutes  having  been  allowed 
for  the  expulsion  of  the  air  by  the  hydrogen  evolved 
from  the  platinum  in  the  bottle,  a  small  spirit  flame  is 
applied  to  the  shoulder  of  the  drawn-out  tube,  so  as  to 
heat  it  to  dull  redness,  at  which  it  should  be  kept  for 
about  a  quarter  of  an  hour;  if  no  ring  of  arsenic  or  sul- 

*  Five  or  six  Grove's  cells  are  very  suitable  for  the  purpose,  but  of 
course  any  battery  which  decomposes  acidulated  water  pretty  briskly 
will  answer. 


286  ARSENIC. 

phide  of  arsenic  is  then  visible  in  the  narrow  point  of 
the  tube,  showing  that  the  sulphuric  acid  is  pure,  the 
solution  to  be  tested  for  arsenic*  is  poured  slowly  down 
the  funnel  tube,  care  being  taken  to  avoid  the  introduc- 
tion of  air-bubbles.  If  much  froth  should  now  make 
its  appearance,  a  drachm  or  two  of  alcohol  may  be 
poured  down  the  tube.  If  no  deposit  of  arsenic  or  of 
(yellow)  sulphide  of  arsenic  be  visible  after  ten  minutes, 
half  a  drachm  of  a  strong  solution  of  washed  sulphurous 
acid  or  of  sulphuretted  hydrogen  is  poured  in,  and  the 
experiment  continued  for  another  quarter  or  half  hour. 
If  any  arsenic  be  present,  either  the  metallic  ring  of 
arsenic,  or  a  greenish-yellow  iridescent  ring  of  sulphide 
of  arsenic,  or  both,  will  be  deposited  in  the  narrow  part 
of  the  tube.f  The  lamp  is  then  removed,  the  tube 
allowed  to  cool,  and  that  part  which  contains  the  deposit 
cut  oft'  by  a  file,  and  gently  warmed  in  a  small  test-tube 
with  a  little  solution  of  carbonate  of  ammonia,  in  which 
the  yellow  sulphide  of  arsenic  will  slowly  dissolve.  The 
tube,  with  the  metallic  portion  of  the  crust,  is  then 
washed,  and  tested  according  to  the  directions  in  748,  a 
b  and  c. 

The  liquid  which  has  been  subjected  to  electrolysis  is 
seldom  exhausted  of  arsenic  unless  a  very  minute  quan- 
tity is  present.  In  order  to  extract  the  remainder,  the 
solution  may  be  mixed  with  a  large  excess  of  a  saturated 
solution  of  sulphuretted  hydrogen,  and  heated  in  a  covered 
beaker  for  an  hour  or  two. 

753a.  The  precipitate  of  sulphide  of  arsenic  mixed 
with  organic  matter  is  collected  on  a  filter,  well  washed, 
dried,  and  thrown  in  small  .portions  into  a  little  nitre 
fused  in  a  porcelain  crucible,  the  filter  being  cut  in 
pieces  and  thrown  in  also.  The  fused  mass  (containing 
the  arsenic  as  arseniate  of  potash);  when  cool,  is  dissolved 

*  If  this  solution  contains  very  much  free  hydrochloric  acid,  it  is 
advisable  to  dilute  it  with  twice  its  volume  of  water. 

f  If  no  odor  of  sulphuretted  hydrogen  be  perceptible  at  the  orifice 
of  the  tube  at  the  end  of  the  experiment,  a  little  more  sulphurous 
acid  or  sulphuretted  hydrogen  should  be  poured  in,  lest  the  liberated 
chlorine  should  have  traversed  the  diaphragm  and  prevented  the 
evolution  of  arseniuretted  hydrogen. 


ARSENIC    IN    ORGANIC    MIXTURES.  287 

in  a  little  water,  the  solution  mixed  with  chloride  of  am- 
monium and  ammonia,  filtered,  if  necessary,  and  well 
stirred  with  solution  of  sulphate  of  magnesia.  After 
standing  for  some  time,  a  highly  crystalline  precipitate 
of  arseniate  of  magnesia  and  ammonia  (2MgO,NH40,As 
O5)  will  separate,  which  may  be  collected  on  a  filter  and 
washed. 

The  arseniate  of  magnesia  and  ammonia  may  be  easily 
distinguished  from  the  phosphate  which  much  resembles 
it,  by  moistening  it  with  nitrate  of  silver,  when  it  assumes 
the  characteristic  red  color  of  arseniate  of  silver,  whilst 
the  phosphate  becomes  bright  yellow.  Of  course  it 
might  also  be  dissolved  (even  after  treating  it  with  nitrate 
of  silver)  in  hydrochloric  acid,  and  tested  by  boiling 
with  hydrosulphuric  acid,  or  by  Marsh's  test. 

SECTION  III. 

V 

Detection  of  Arsenic  in  Organic  Mixtures  containing  loth 
Liquid  and  Solid  Matters;  such  as  the  contents  of  a  Stomach, 
vomited  matters,  &c. 

754.  When  the  liquid  and  solid  portions  of  the  mix- 
ture are  found  capable  of  ready  separation,  either  by 
subsidence  or  filtration,  it  is  generally  better  to  examine 
each  of  them  separately.     When  this  is  not  the  case,  see 
paragraph  758. 

755.  Examination   of  the   liquid  portion. — The   clear 
liquid,  after  the  removal  of  the  solid  matter,  either  by 
filtration  or  otherwise,  is  to  be  examined  in  the  manner 
described  in  paragraph  751. 

756.  Examination  of  the  solid  portion* — This  should 
first  be  examined  for  any  small  lumps  of  arsenious  acid, 
which,  in  cases  of  poisoning,  are  often  to  be  found  adhe- 
ring to  the  coats  of  the  stomach.     These  should  be  care- 
fully picked  out,  and  tested  according  to  the  directions 
given  in  paragraphs  742 — 744. 

757.  The  solid  or  semi-solid  organic  matter  is  then  to 
be  heated  on  the  water-bath  with  dilute  hydrochloric 

*  In  some  cases  it  may  be  of  importance  to  note  the  weight  of  the 
solid  matter. 


288  ARSENIC. 

acid,  containing  about  one-tenth  of  the  strong  acid.  A 
part  of  the  acid  solution  may  then  be  boiled  with  copper 
strips,  which  are  to  be  dried,  and  examined  for  arsenic 
in  the  manner  before  described  (749).  The  remainder  of 
the  acid  solution  may  be  examined  by  753,  and  the  un- 
dissolved  solid  portions  by  761. 

758.  When  the  organic  matter  is  viscid,  and  incapable 
of  ready  separation  into  solid  and  liquid  portions  (754), 
it  may  be  mixed  with  a  little  dilute  hydrochloric  acid, 
well  stirred  together,  and  boiled;  if  the  solution  thus  ob- 
tained be  sufficiently  thin,  it  may  be  filtered,  and  dealt 
•with  as  in  757,  but  otherwise  it  must  be  treated  accord- 
ing to  759. 

SECTION  IV. 

Detection  of  Arsenic  in  the  Tissues,  and  in  other  solid  Organic 

Matters. 

759.  In  medico-legal  investigations  as  to  the  presence 
of  arsenic,  it  is  absolutely  necessary,  in  case  none  of  the 
poison  can  be  detected  in  the  stomach  and  its  contents, 
to  examine  the  various  tissues  of  the  body;  since  the 
poison,  when  introduced  into  the  stomach  during  life, 
becomes  gradually  absorbed  and  diffused  through  the 
whole  system,  and  may  be  found  in  the  blood,  urine, 
muscles,  and  viscera,  especially  the  liver.     It  is  therefore 
advisable  to  examine  each  of  these  for  the  poison ;  and  it 
should  never  be  concluded,  that  because  it  cannot  be  de- 
tected in  the  stomach  and  its  contents,  none  is  to  be 
found  in  other  parts  of  the  body.     Should  the  patient, 
however,  survive  during  several  days  after  swallowing 
the  poison,  it  is  possible  that  the  whole  of  it  may  be  eli- 
minated from  the  body  ;  in  which  case  no  trace  of  it  will 
afterwards  be  detected. 

760.  If  the  solid  matters  to  be  examined  have  under- 
gone putrefaction,  the  arsenious  acid  may  have   been 
partly  converted  into  sulphide  of  arsenic,  which  is  some- 
times perceived  in  bright  yellow  patches. 

761.  The  solid  matter  intended  for  examination*  is  to 

*  The  part  of  the  body  in  which  the  poison  is  most  likely  to  be 
found  is  the  liver,  which  should  always  be  preferred  for  these  experi- 
ments. The  pancreas,  kidneys,  and  urine,  should  also,  if  possible,  be 
examined,  before  deciding  on  the  absence  of  arsenic. 


DETECTION    OF    ARSENIC    IN    THE    TISSUES.      289 

be  cut  up  and  heated  on  tlio  water-bath  for  an  hour  or 
two  with  hydrochloric  acid,  consisting  of  one  part  of 
the  strong  acid  to  eight  or  ten  of  water.  The  mixture 
is  then  filtered  through  fine  muslin,  in  order  to  separate 
the  more  solid  matters;  and  the  clear  liquid  thus  obtained 
is  concentrated  to  about  half  its  bulk,  by  evaporation  on 
the  water-bath,  and  treated  as  in  751.  The  undissolved 
solid  portions  are  heated  in  a  porcelain  dish,  placed  upon 
a  water-bath,  with  a  mixture  of  six  measures  of  water 
and  one  of  hydrochloric  acid,  to  which  chlorate  of  potash 
is  added  in  small  portions,  with  constant  stirring,  until 
the  solid  has  disintegrated,  and  the  liquid  is  fit  for  filtra- 
tion. The  further  treatment  is  then  conducted  as  in  753. 

If  a  galvanic  battery  be  not  procurable,  the  solution 
obtained  by  means  of  hydrochloric  acid  and  chlorate  of 
potash  is  evaporated  to  a  small  bulk,  mixed  with  a  strong 
solution  of  washed  sulphurous  acid,*  until  it  has  a  de- 
cided odor  of  the  gas,  heated  in  a  flask  placed  in  a 
water  bath,  until  the  odor  of  sulphurous  acid  has  dis- 
appeared, mixed  with  a  large  excess  of  a  saturated  solu- 
tion of  sulphuretted  hydrogen,  and  digested  for  some 
time  at  a  moderate  heat.  The  precipitate  of  sulphide  of 
arsenic,  which  is  never  pure  yellow,  but  dingy,  from  the 
presence  of  organic  matter,  is  collected  upon  a  small  fil- 
ter, washed,  and  treated  as  in  753a. 

The  solution  obtained  by  treatment  with  hydrochloric 
acid  and  chlorate  of  potash  might  also  be  tested  by 
Marsh's  or  by  Eeinsch's  test,  but,  if  the  solution  is  at  all 
viscous,  the  frothing  is  a  serious  obstacle  to  the  applica- 
tion of  the  former,  and  the  introduction  of  copper  in  the 
latter  test  unfits  the  solution  for  further  examination  if  it 
should  be  necessary. 

Should  it  be  required  to  examine  for  arsenic  the  orga- 
nic matter  left  undissolved  by  hydrochloric  acid  and  chlo- 
rate of  potash,  it  may  be  dried,  mixed  with  five  or  six 
times  its  weight  of  pure  nitre,  and  thrown  by  degrees 
into  a  red-hot  dish  or  crucible.  The  deflagrated  mass, 
which  would  contain  arseniate  of  potash,  is  dissolved  in 
as  little  water  as  possible,  acidulated  with  hydrochloric 

*  To  reduce  the  arsenic  acid  (As05)  to  arsenious  acid  (As03). 
25 


290  ARSENIC. 

acid,  gently  heated,  and  if  necessary,  filtered.  The  clear 
liquid  is  mixed  with  a  few  drops  of  solution  of  sulphate 
of  magnesia  and  a  considerable  excess  of  ammonia,  and 
after  being  well  stirred,  is  set  aside  for  twenty-four  hours. 
The  precipitate  will  contain  the  arsenic  in  the  form  of 
arseniate  of  magnesia  and  ammonia  (2MgO,NH40,AsO5), 
together  with  earthy  phosphates  derived  from  the  organic 
matter.  It  is  collected  upon  a  filter,  washed  with  dilute 
ammonia  (pure  water  dissolves  it),  and  dissolved  in  as 
little  dilute  hydrochloric  acid  as  possible.  The  solution 
may  then  be  tested  either  by  Marsh's  or  the  electrolytic 
test. 

761a.  Another  method  which  has  been  found  very  use- 
ful for  separating  arsenic  from  organic  matters,  consists 
in  drying  them  upon  a  water-bath,  digesting  in  a  covered 
vessel  with  moderately  concentrated  hydrochloric  acid, 
separating  the  solid  matters  by  filtration,  and  distilling, 
the  acid  vapor  being  condensed  in  a  flask  containing 
water.  The  arsenic  is  found  in  the  distillate,  having 
passed  over  as  terchloride  of  arsenic  (AsCl3)  and  may 
be  detected  by  the  ordinary  tests. 

761&.  Detection  of  arsenite  of  copper  in  paper-hangings 
and  other  fabrics.  A  very  ready  method  of  effecting  this 
consists  in  soaking  the  fabric  to  be  tested  in  a  little  solu- 
tion of  ammonia;  the  blue  solution  which  will  be  found 
if  copper  is  present,  is  acidulated  with  hydrochloric  acid 
and  boiled  with  clean  copper  (749). 

SECTION  V. 
Quantitative  Determination  of  Arsenic. 

?62.  The  exact  determination  of  the  quantity  of  arsenic 
present  in  a  mixture  containing  much  organic  matter  is 
attended  with  great  difficulty.  In  general,  a  sufficiently 
accurate  estimate  of  the  amount  may  be  found  by  com- 
paring the  crusts  obtained  by  Marsh's  test  with  those 
furnished  by  known  quantities  of  arsenious  acid,  but 
should  a  direct  determination  be  necessary,  it  may  be 
effected  by  a  process  of  which  an  outline  is  here  given, 
though  without  the  minute  details  of  manipulation  requi- 
site for  perfect  accuracy. 


QUANTITATIVE    DETERMINATION    OF   ARSENIC.    291 

After  having  obtained  the  arsenic  in  a  state  of  solution 
by  heating  the  organic  matter  with  hydrochloric  acid  and 
chlorate  of  potash,  as  described  above,  the  clear  liquid 
is  mixed,  in  a  flask,  with  a  strong  solution  of  bisulphite 
of  soda  until  it  smells  very  strongly  of  sulphurous  acid, 
even  after  being  heated  for  some  minutes  in  a  water-bath 
to  reduce  the  arsenic  acid  (As05)  to  the  state  of  arsenious 
acid  (As03).  The  application  of  heat  is  continued  till 
the  smell  of  sulphurous  acid  has  disappeared,  and  the 
solution  is  thoroughly  saturated  with  sulphuretted  hy- 
drogen, after  which  the  flask  is  corked  and  set  aside  in 
a  warm  place  for  some  hours.  The  precipitate,  containing 
sulphide  of  arsenic  mixed  with  organic  matter,  is  col- 
lected upon  a  filter,  washed,  and  dried.  The  dry  preci- 
pitate is  mixed  with  about  six  parts  of  nitre  and  six  parts 
of  dry  carbonate  of  soda,  and  projected,  by  degrees,  to 
gether  with  the  fragments  of  the  filter,  into  a  red-hot  por- 
celain crucible.  The  deflagrated  mass,  containing  arse- 
riiateof  potash,  is  dissolved  in  a  little  water,  the  solution 
filtered  if  necessary,  and  mixed  with  chloride,  of  ammo- 
nium, ammonia,*  and  sulphate  of  magnesia.  After  being 
well  stirred,  it  is  set  aside  for  twenty-four  hours,  when 
the  arseniate  of  magnesia  and  ammonia  will  have  sepa- 
rated as  a  crystalline  precipitate,  which  must  be  collected 
on  a  weighed  filter,  washed  with  dilute  ammonia,  dried 
at  212°  and  weighed  (753a).  The  quantity  of  arsenious 
acid  is  calculated  by  the  proportion, 
2MgO,NH40,AsO5  -f  HO.  As03. 

190  :      '99     ::     Weight  of  the  precipitate    :    x. 

*  Should  any  precipitate  be  caused  by  the  ammonia,  it  must  be 
filtered  off. 


292          ELECTKOLYTIC    TEST    FOR    ANTIMONY. 


CHAPTER   II. 

ANTIMONY. 

763.  THE  form  in  which  'antimony  is  generally  met 
with  in  medico-legal  investigations,  is  the  double  tartrate 
of  antimony  and  potash  (KO,Sb03,C8H4O10  +  Aq),  com- 
monly called  tartar-emetic  or  tartarized  antimony,  which 
is  often  taken  medicinally,  and  occasionally  as  a  poison. 
It  may  be  recognized  by  applying  to  its  solution  the  fol- 
lowing tests. 

(a)  Hydrochloric  acid,  which  gives  a  white  precipitate 
of  teroxide  of  antimony  (Sb03)  soluble  in  excess. 

(6)  Hydrosulphuric  acid,  in  the  solution  form  (a),  gives 
a  bright  orange  precipitate. 

(c)  Hydrochloric  acid  and  metallic  copper  (749),  on  the 
application  of  heat,  will  give  a  purplish  black  deposit  of 
metallic  antimony,  upon  the  surface  of  the  copper.     The 
latter,  when  dried  and  heated  in  a  tube,  will  not  yield  a 
crystalline  sublimate  like  arsenic,  but  may  give  a  white 
amorphous  deposit  on  strongly  heating.     The  deposit  is 
dissolved  by  boiling  the  strip  of  copper  in  a  dilute  solu- 
tion of  potash,  and  if  the  solution  be  treated  with  sul- 
phuretted hydrogen,  filtered  from  any  precipitate,  and 
acidulated  with  hydrochloric  acid,  the  orange  sulphide 
of  antimony  is  precipitated. 

(d)  Marsh's  test  (745)  will  yield  metallic  crusts  of  anti- 
mony, as  with   arsenic,  but   the   antimonial  crusts  are 
readily  distinguished  by  the  following  characters.     (1) 
They  are  much  less  volatile  than  those  of  arsenic,  and 
are  therefore  deposited  very  much  nearer  to  the  heated 
portion  of  the  tube.     (2)  They  give  no  crystalline- subli- 
mate when  heated  in  a  tube,  but,  with  a  strong  heat,  an 
amorphous  sublimate.     (3)  Antimonial   crusts  will  not 
dissolve  easily  iu  solution  of  chloride  of  lirne;  but  (4) 


ANTIMONY   IN    ORGANIC    MATTER.  293 

they  do  so  at  once  in  yellow  sulphide  of  ammonium,  and 
if  the  solution  be  slowly  evaporated,  it  leaves  an  orange 
residue  of  sulphide  of  antimony  (SbS3).  (5)  When  oxi- 
dized by  nitric  acid  and  evaporated,  the  antimonial  crust 
gives  a  residue  which  refuses  to  dissolve  in  water  and 
produces  a  dirty  gray  precipitate  with  nitrate  of  silver 
(compare  748  a,  6,  c). 

(e)  The  electrolytic  test  evolves  antimonietted  hydro- 
gen far  less  readily  than  arsenietted  hydrogen,  most  of 
the  antimony  being  deposited  as  a  black  coating  upon 
the  platinum  plate  connected  with  the  zinc  end  of  the 
battery.  If  the  plate  be  washed,  and  gently  heated  with 
a  yellow  sulphide  of  ammonium,  it  dissolves  the  anti- 
mony and  leaves  the  orange  residue  when  evaporated. 
By  pouring  a  strong  solution  of  hydrosulphuric  acid 
down  the  funnel-tube  at  the  commencement  of  the  elec- 
trolysis, it  will  entirely  prevent  the  evolution  of  antimo- 
nietted hydrogen,  whilst  it  promotes  that  of  arsenietted 
hydrogen. 

(/)  If  a  solution  of  antimony,  acidified  with  hydro- 
chloric acid  be  poured  into  a  platinum  capsule,  or  placed 
upon  platinum  foil  (or  even  upon  a  gold  or  silver  coin), 
and  a  strip  of  zinc  (or  iron,  such  as  a  knife  blade)  be 
placed  in  it,  a  black  deposit  of  antimony  will  be  found 
around  the  point  of  contact  of  the  two  metals.  The  de- 
posit may  be  tested  by  placing  a  drop  of  yellow  sulphide 
of  ammonium  upon  it,  and  evaporating  to  obtain  the 
orange  residue,  which  should  be  compared  with  the  resi- 
due left  by  a  drop  of  sulphide  of  ammonium  alone  upon 
the  uncoated  metallic  surface.* 

SECTION  I. 
Detection  of  Antimony  in  the  presence  of  Organic  Matter. 

764.  For  the  detection  of  antimony  in  organic  liquids 
and  solids,  the  same  methods  of  proceeding  are  adopted 
as  in  the  case  of  arsenic  (751 — 761),  the  antimony  being 
recognized  by  the  characters  described  in  763. 

765.  Should  both  metals  be  present,  they  may  still  be 

» 

*  Of  course  a  surface  of  silver  would  be  blackened  by  the  sulphide. 

25* 


294  MERCURY. 

easily  detected,  unless  there  was  a  very  great  dispropor- 
tion between  them,  by  the  behavior  of  the  crusts  obtained 
in  Marsh's  test, 

766.  Even  if  one  of  the  metals  largely  predominates, 
the  electrolytic  test  permits  the  detection  of  both ;  it  is 
only  necessary  to  allow  the  electrolysis  to  proceed  for 
five  or  ten  minutes  in  order  to  deposit  the  antimony  on 
the  negative  plate  before  adding  the  hydrosulphuric  acid, 
which  will  at  once  arrest  the  evolution  of  the  antimoni- 
etted  hydrogen,  and  if  the  reduction  tube  be  changed,  a 
deposit  of  pure  arsenic  or  sulphide  of  arsenic  will  be 
obtained. 

SECTION  II. 
Quantitative  Determination  of  Antimony. 

767.  The  remarks  in  paragraph  762,  upon  the  deter- 
mination of  the  quantity  of  arsenic  will  apply  also  in 
the  case  of  antimony,  and  precisely  the  same  steps  must 
be  taken  in  order  to  ascertain  the  amount  of  the  latter 
metal,  except  that  dried  nitrate  of  soda  should  be  used 
instead  of  nitrate  of  potash  for  the  deflagration  of  the 
sulphide.     On  digesting  the  fused  mass  in  the  cold,  with 
a  little  water,  almost  the  whole  of  the  antimony  will  be 
left  in  the  form  of  antimoniate  of  soda  (NaO,SbO5),  which 
must  be  collected  upon  a  filter,  washed  with  cold  water, 
dried,  and  fused  with  five  or  six  times  its  weight  of  cya- 
nide of  potassium  in  a  porcelain  crucible,  until  the  anti- 
mony has  collected  into  a  globule  at  the  bottom  of  the 
fused  mass.    The  latter  is  dissolved,  when  cold,  in  water, 
and  the  metallic  button  weighed.    Each  grain  of  antimony 
corresponds  to  2*73  grains  of  crystallized  tartar-emetic. 


CHAPTER  III. 

MERCURY. 

768.  THE  moat  common  preparation  of  mercury,  by 
which  life   has  been   sacrificed  or  endangered,  is  the 


MERCURY    IN    ORGANIC    MIXTURES. 

chloride  (IlgCl),  commonly  called  corrosive  sublimate ; 
the  subchloride,  or  calomel  (IIg2Cl),  the  red  oxide  (HgO), 
and  some  of  the  other  compounds,  are  also  sometimes 
administered,  either  criminally  or  accidentally,  with  fatal 
effect,  and  may  consequently  have  to  be  looked  for  by 
the  medical  jurist.  In  the  process  I  am  about  to  describe, 
however,  any  of  these  compounds  will  be  brought  into  a 
state  of  solution ;  after  which  the  mercury  contained  in 
them  may  readily  be  detected  by  the  proper  tests. 

SECTION  I. 
Detection  of  Mercury  in  Organic  Mixtures. 

769.  When  the  presence  of  mercury  is  suspected  in  an 
organic  mixture,  such  as  the  contents  of  a  stomach,  the 
solid  and  liquid  portions  of  the  matter  to  be  examined 
may  be  separated  from  each  other,  either  by  filtration  or 
decantation,  provided  the  separation  takes  place  readily; 
or  if  this  is  not  the  case,  the  whole  of  the  mixture  may 
be  treated  with  acid,  and  examined  in  the  manner  de- 
scribed in  paragraphs  774-776. 

770.  Examination   of  the   liquid  portion. — The   liquid 
portion  may  be  first  examined.     Acidify  it  with  a  few 
drops  of  hydrochloric  acid,  and  boil  the  mixture  for  a 
quarter  or  half  an  hour,  with  two  or  three  strips  of  clean 
copper  foil.     If  any  mercury  is  present  in  the  liquid,  it 
will  in  this  way  be  entirely  separated  from  the  solution 
and  deposited  on  the  surface  of  the  copper.     The  latter 
is  then  removed  from  the  acid  liquid,  and  washed  with 
a  little  dilute  solution  of  ammonia,  in  order  to  remove 
from  the  surface  any  adhering  oxide  or  subsalt  of  copper. 
The  strips   are  then  dried  by  gentle  pressure  between 
folds  of  bibulous  paper,  and  placed  in  a  small  and  perfectly 
dry  German  glass  tube,  three  or  four  inches  long,  closed 
at  one  end. 

771.  The  heat  of  a  spirit  lamp  is  then  applied  to  the 
bottom  of  the  tube  containing  the  copper  strips ;  when, 
if  any  mercury  has  been  deposited  upon  them,  it  will  be 
volatilized  by  the  heat,  and  condensed  in  the  cooler  part  of 
the  tube,  forming  a  delicate  and  dew-like  ring  of  minute 
globules  of  metallic  mercury;  the  real  nature  of  which  may 


296  MERCURY    IN    ORGANIC    MIXTURES. 

be  at  once  seen  with  the  assistance  of  a  common  lens,  if  not 
with  the  naked  eye. 

771  a.  If  the  sublimate  is  so  minute  that  the  globules 
are  not  distinguishable,  it  may  be  gently  rubbed  with  a 
glass  rod  to  unite  the  small  globules.  The  strip  of  copper 
may  be  shaken  out  of  the  tube,  a  very  minute  particle 
of  iodine  introduced,  and  a  gentle  heat  applied  to  vaporize 
it.  The  mercurial  sublimate  will  thus  be  converted  into 
iodide  of  mercury,  which  is  yellow  at  first,  and  becomes 
scarlet  when  rubbed  with  a  glass  rod  (Lassaigne). 

772.  If,  in  the  experiment  above  described  (771),  the 
appearance  of  metallic  globules  is  distinctly  visible,  it 
will  scarcely  be  necessary  to  apply  any  further  tests  to 
prove  the  presence  of  mercury,  since  no  other  substance 
is  capable  of  producing  such  a  sublimate.     If,  however, 
any  doubt  exists  as  to  the  nature  of  the  sublimate,  the 
following  experiments  may  be  made : — 

773.  Kemove  the  copper  from  the  tube,  and  dissolve  the 
sublimate  in  nitrohydrochloric  acid ;  by  which  the  mer- 
cury, if  present,  will  be  converted  into  the  soluble  chloride 
(HgCT).     Expel  the  excess  of  acid  by  evaporation  at  a 
gentle  heat ;  and  apply  to  an  aqueous  solution  of  the 
residue,  the  following  tests : — 

Jo)  Solution  of  iodide  of  potassium  (Kl)  gives  a  brilliant 
precipitate  of  iodide  of  mercury  (Hgl),  which  is  very 
soluble  in  excess  of  the  iodide  of  potassium. 

(b)  Solution  of  potash  gives  a  yellow  precipitate  of 
hydrated  oxide  of  mercury,  which    is   insoluble  in  an 
excess  of  the  precipitant. 

(c)  A  solution  of  hydrosulphuric  acid   (sulphuretted 
hydrogen),  or  a   drop  or    two   of  hydrosulphate  of  am- 
monia, forms  at  first  a  white  precipitate,  consisting  of  a 
double  compound  of  chloride  and  sulphide  (2HgS,HgCl), 
which,  unless  the  precipitant  be  added  very  sparingly, 
almost  immediately  becomes  darker,  owing  to  the  admix- 
ture of  the  black  sulphide  (HgS).     If  the  precipitant  be 
added  in  excess,  the  whole  of  the  precipitate  becomes 
black. 

(d)  The  dry  mercurial  salts,  when  mixed  with  car- 
bonate of  soda,  and  heated  in  a  narrow  tube  before  the 


ELECTKOLYTIC    TEST    FOR    MERCURY.          297 

blowpipe,    yields   a   sublimate   of    minute   globules   of 
metallic  mercury. 

774.  Exa  in  tin dinn  of  the  solid  portion. — The  solid  portion 
of  the  mixture   may  contain  mercury  in  combination 
with  certain  animal  matters,  besides  particles  of  calomel, 
oxide,  or  some  other  mercurial  compound.     It  may  first 
be  examined  for  any  visible  fragments  of  these,  which,  if 
detected,  may  be  picked  out,  and  tested  for  mercury,  by 
mixing   them,   when  dry,  with  carbonate  of  soda,  and 
heating  the  mixture  in  a  small  tube  before  the  blowpipe; 
when  the  mercury  will  be  sublimed  into  the  cooler  part 
of  the  tube  (773  d). 

775.  The  rest  of  the  solid  matter  may  now  be  warmed 
with  a  little  hydrochloric  acid  and  chlorate  of  potash,  as 
directed  in  761 ;  one  part  of  the  filtered  solution  may  be 
tested  by  boiling  with  copper,  and  the  other   may  be 
subjected  to  electrolysis  according  to  the  directions  given 
in  753. 

If  mercury  be  present  in  the  solution,  it  will  be  de- 
posited upon  the  negative  plate  (connected  with  the  zinc 
end  of  the  battery),  and  may  be  readily  detected  by 
boiling  the  plate  in  a  few  drops  of  nitric  acid,  expelling 
the  greater  excess  of  the  latter  by  evaporation,  rendering 
the  solution  alkaline  with  ammonia  (because  the  free 
nitric  acid  would  dissolve  the  copper),  acidifying  very 
slightly  with  hydrochloric  acid,  and  boiling  with  a  slip 
of  clean  copper  foil,  which  may  afterwards  be  washed 
and  heated  in  a  tube.  If  the  negative  plate  be  of  gold 
(or  of  platinum  gilt  by  immersing  it  whilst  attached  to 
the  battery,  in  a  solution  of  cyanide  of  gold  in  cyanide 
of  potassium),  the  mercury  will  of  course  be  easily  recog- 
nized by  the  silvery  appearance  of  the  deposit. 

In  the  absence  of  a  galvanic  battery,  the  solution 
obtained  by  means  of  hydrochloric  acid  and  chlorate  of 
potash  may  be  mixed  with  excess  of  hydrosulphuric  acid 
and  heated  for  some  time,  when  the  black  sulphide  of 
mercury  will  be  deposited,  and  may  be  collected  on  a 
filter  and  washed ;  it  will  be  found  nearly  insoluble  in 
hot  nitric  acid,  but  readily  soluble  in  a  mixture  of  nitric 
and  hydrochloric  acids.  The  presence  of  mercury  in  the 
solution  may  be  proved  by  evaporating  it  to  a  small  bulk, 


298  LEAD. 

adding  ammonia  in  excess,  then   hydrochloric  acid  in 
excess,  and  boiling  with  metallic  copper  (770). 

776.  A  very  small  quantity  of  mercury  may  also  be 
detected  by  placing  the  solution  upon  a  gold  or  copper 
coin,  and  touching  the  gold,  through  the  liquid,  with  a 
piece  of  zinc  or  the  blade  of  a  knife,  when  a  silvery 
deposit  will  be  formed  around  the  point  of  contact,  and 
will  disappear  when  the  washed  coin  is  gently  heated. 

SECTION  II. 
Detection  of  Mercury  in  the  Tissues. 

777.  When  the  presence  of  mercury  is  suspected  in 
the  viscera  or  other  tissues  of  the  body,  the  part  intended 
for  examination  should  first  be  cut  into  thin  slices,  and 
heated  with  hydrochloric  acid  and  chlorate  of  potash 
(761)  ;  by  which  means  any  mercury  that  may  be  present 
will  be  converted  into  the  bichloride,  and  thus  brought 
into  a  state  of  solution.     The  undissolved  matter  is  then 
separated   by  filtration  or  decantation,   and  the  liquid 
portion  evaporated  to  a  small  bulk  on  a  water-bath,  and 
treated  as  in  775. 


CHAPTER  IY. 

LEAD. 

778.  ALTHOUGH  instances  of  criminal  poisoning  with 
compounds  of  lead  are  of  comparatively  rare  occurrence, 
still  the  accidental  admission  of  it  into  the  system,  either 
in  the  form  of  the  solid  carbonate  (white  lead)  so  exten- 
sively employed  in  the  arts,  or  through  ^the  medium  of 
water   impregnated   with   it,    very   frequently   leads   to 
serious  and  even  fatal  results;  so  that  its  detection  is 
often  a  matter  of  grave  importance. 

779.  In  testing  for  minute  quantities  of  lead,  it  must 
be  borne  in   mind   that   several   of  the  test   solutions 
employed  in  analysis,  when  kept  even  for  a  few  weeks 


WATER    IMPREGNATED    WITH    LEAD.  299 

in  bottles  of  flint  glass,  dissolve  out  very  perceptible 
traces  of  the  metal  from  the  glass,  in  which  it  is  present 
in  considerable  quantity ;  so  that,  unless  the  experimenter 
is  on  his  guard,  he  may  be  led  to  suppose  that  he  has 
detected  the  metal  in  the  liquid  which  he  is  examining, 
while,  in  fact,  he  has  himself  introduced  it  in  one  of  his 
reagents.  Solutions  of  potash  and  soda,  and  their  car- 
bonates, are  especially  liable  to  become  in  this  way 
impregnated  with  lead ;  and  several  other  saline  solutions 
also,  under  peculiar  circumstances,  do  the  same,  though 
more  slowly,  and  in  a  less  degree.  On  this  account  it 
is  always  advisable  to  test  each  of  the  reagents  employed 
with  solution  of  hydrosulphuric  acid  in  large  excess, 
which  will,  if  any  traces  of  lead  are  present,  give  the 
liquid  a  more  or  less  decided  brown  tint ;  or  even  cause 
a  black  precipitate,  if  the  quantity  of  metal  is  at  all 
considerable. 

SECTION  I. 
Examination  of  Water  suspected  to  be  impregnated  with  Lead. 

780.  The  water  intended  for  examination  (which  should 
always  be  tested  as  soon  as  possible  after  being  taken 
from  the  cistern  or  pipe  in  which  it  has  been -standing) 
is  placed  in  a  beaker  or  bottle  of  German  or  green  glass, 
free  from  lead,  the  surface  of  which  should  be  washed 
perfectly  clean  with  distilled  water.  A  stream  of  hydro- 
sulphuric  acid  (sulphuretted  hydrogen)  gas  is  then  trans- 
mitted through  water,  until  the  latter  smells  distinctly 
of  the  gas.  When  lead  is  present,  the  liquid  will  gene- 
rally assume  a  brown  tint  almost  immediately,  unless 
the  quantity  of  lead  is  extremely  small ;  but  before  de- 
ciding that  the  water  is  pure,  it  should  be  set  aside  for  a 
few  hours,  after  being  saturated  with  the  gas,  during  which 
time  the  sulphur  will  be  partially  precipitated,  owing  to 
the  decomposition  of  the  hydrosulphuric  acid  by  the 
oxygen  of  the  air,  mixed,  if  any  trace  of  lead  is 
present,  with  a  little  sulphide  (PbS),  which  will  give  the 
sediment  a  more  or  less  decided  brown  or  fawn  color. 
If,  on  the  contrary,  the  water  continues  colorless,  and 
the  precipitated  sulphur  is  white,  or  of  a  very  pale 


300  DETECTION    OF    LEAD    IN 

sulphur  color,  it  may  be  concluded  that  no  perceptible 
trace  of  lead  is  contained  in  the  water. 

781.  The  most  satisfactory  method   of  applying  this 
test  for  lead  in  waters  is  the  following.     Two  test-tubes 
of  clear  white  glass,  free  from  lead,  about  nine  inches 
long,  and  half  an  inch  in  diameter,  are  nearly  filled,  one 
with  pure  distilled  water,  the  other  with  the  water  under 
examination,  to  which  a  few  drops  of  pure  acetic  acid 
are  added  to  prevent  the  precipitation  of  any  sulphide  of 
iron.     A  similar  quantity  of  acetic   acid   having  been 
added  to  the  distilled  water,  for  the  purpose  of  compari- 
son, the  contents  of  both  tubes  are  tested  either  with  a 
clear  solution   of   hydrosulphuric   acid,   or  with   a  few 
bubbles  of  the  gas.    By  holding  both  tubes,  after  shaking, 
over  a  sheet  of  white  paper,  so  that  the  eye  may  look 
along  the  axis  of  each  tube,  the  slightest  trace  of  lead 
may  be  discovered  by  the  dark  color  of  the  liquid,  and 
all  fallacy  is  excluded  by  the  comparison  with  the  pure 
water.     It  is  evident  that  by  comparing  the  result  with 
those  furnished  by  solutions  containing  known  quantities 
of  lead,  a  close  approximation  to  the  amount  of  the  latter 
may  be  arrived  at. 

782.  Lead  may  also  be  detected  in  waters  by  evapo- 
rating a  quart  to  dryness,  heating  the  residue  with  strong 
hydrochloric  acid,  and  mixing  -the  hydrochloric  solution 
with  a  large  excess  of  strong  solution  of  hydrosulphuric 
acid,  when    the  purplish  black  precipitate,  or  color,  of 
sulphide  of  lead  will  be  obtained. 

SECTION  II. 
Detection  of  Lead  in  Organic  Mixtures. 

783.  If  the  organic  matter  to  be  examined  is  a  mix- 
ture of  solid  and  liquid,  such  as  the  contents  of  a  stomach, 
the  two  portions  should,  if  practicable,  be  separated  by 
filtration  through  paper  or  muslin;  having  been  previ- 
ously diluted,  if  necessary,  with  a  little  water,  and  gently 
heated  with  a  drachm  or  two  of  pure  acetic  acid,  which 
will  cause  the  liquid  to  pass  more  readily  through  the 
pores  of  the  filter.     The   liquid   portion  may  be  first 
tested ;  and  in  case  none  of  the  metal  can  be  detected  in 


ORGANIC    MIXTURES.  301 

it,  the  solid  or  semi-solid  matter  may  be  afterwards  ex- 
amined (788). 

78-i.  Examination  of  the  liquid  portion. — A  current  of 
hydrosulphuric  acid  gas  is  passed  through  the  liquid  for 
about  a  quarter  of  an  hour,  by  which  means  any  lead 
that  may  be  dissolved  will  be  precipitated  as  the  black 
sulphide.*  This  is  to  be  separated  by  filtration,  and  the 
greater  part  of  it  digested,  with  the  aid  of  a  gentle  heat, 
in  moderately  dilute  nitric  acid;  a  small  portion  being 
retained  for  examination  with  the  blowpipe  (787). 

785.  When  the  'sulphide  is  for  the  most  part  decom- 
posed by  the  nitric  acid  (which  may  be  known  by  the 
undissolved   residue,  consisting  chiefly   of  sulphur,  be- 
coming nearly  white),  the  clear  solution  is  to  be  filtered 
from  the  insoluble  matter,  and  tested  in  the  following 
manner  (786);  the  undissolved  residue  being  also  retained, 
in  case  it  may  be  required  for  subsequent  examination 
(787).     The  digestion  in  warm  acid  should  not  be  con- 
tinued longer  than  necessary,  since  the  prolonged  action 
of  the  nitric  acid  might  have  the  effect  of  oxidizing  the 
sulphur  as  well  as  the  lead,  forming  sulphuric  acid,  which 
would  combine  with  the  oxide  of  lead,  and  precipitate  it 
from  the  solution  in  the  form  of  the  insoluble  sulphate 
(PbO,S03). 

786.  The  clear  solution  (785)  is  now  to  be  evaporated 
to  dryness  on  a  water-bath,  in  order  to  expel  the  excess 
of  nitric  acid;  after  which  the  residue  is  to  be  redissolved 
in  warm  water,  and  tested  in  the  following  manner;  or, 
if  the  quantity  is  small,  the  tests  &,  c,  and  d  only  need  be 
applied. 

(a)  Hydrosulphuric  acid,  and  hydrosulphate  of  ammonia 
cause  a  black  precipitate  of  sulphide  of  lead  (PbS). 

(b)  Dilute  sulphuric  acid,  or  a  solution  of  sulphate  of 
soda,  gives  a  white  precipitate  of  sulphate  of  lead  (PbO, 
S03),  which  is  insoluble,  or  nearly  so,  in  acids,  but  gra- 
dually dissolves  in  a  solution  of  caustic  potash. 

(c)  The  sulphate  formed  in  &,  after  being  washed  with 

*  Minute  quantities  of  lead  escape  precipitation  in  liquids  contain- 
ing organic  matter,  and  can  only  be  detected  by  evaporating  to  dry- 
ness  and  incinerating  the  residue  (788). 

26 


302    DETECTION    OF    LEAD    IN    ORGANIC    MIXTURES. 

distilled  water,  is  instantly  blackened  when  moistened 
with  hydrosulphate  of  ammonia  or  a  solution  of  hydro- 
sulphuric  acid,  owing  to  the  formation  of  the  black  sul- 
phide. The  sulphate  of  lead  may  in  this  way  be  readily 
distinguished  from  the  sulphates  of  baryta  and  strontia, 
which  it  resembles  in  many  respects. 

(d)  A  solution   of  iodide  of  potassium  (KI)   throws 
down  a  bright  yellow  precipitate  of  iocjjde  of  lead  (Pbl), 
which  is  soluble  in  hot  water,  and,  on  cooling,  separates 
from  the  solution  in  the  form  of  brilliant  crystalline 
scales  of  great  beauty. 

(e)  Hydrochloric  acid,  or  a   solution   of  chloride   of 
sodium,  causes,  if  the  solution  is  not  very  dilute,  a  white 
crystalline  precipitate  of  chloride  of  lead  (PbCl),  which 
dissolves  when  the  mixture  is  heated,  and  crystallizes  in 
the  form  of  delicate  needles  as  the  solution  cools. 

(/)  Chromate  of  potash  (KO,CrO^)  gives  a  rich  yellow 
precipitate  of  chromate  of  lead  (PbO,Cr03),  which  is 
soluble  in  potash,  and  insoluble  in  dilute  acids. 

(g)  If  any  of  the  precipitates  formed  in  the  above 
experiments  be  dried,  and  heated  on  charcoal,  with  or 
without  a  little  dried  carbonate  of  soda,  in  the  inner 
flame  of  the  blowpipe,  minute  metallic  beads  will  be 
obtained;  which  may  be  recognized  as  lead  by  their 
softness  and  malleability ;  a  yellow  incrustation  of  oxide 
of  lead  appears  upon  the  charcoal. 

787.  If  no  decided  indication  of  lead  can  be  obtained 
from  the  nitric  acid  solution,  the  other  portion  of  sulphide 
(784),  and  also  the  residue  which  proved  insoluble  in  the 
acid  (785),  may  be  dried,  mixed  with  carbonate  of  soda, 
and  heated  in  the  inner  flame  of  the  blowpipe;  when,  if 
any  lead  is  present,  it  will  be  speedily  reduced  to  the 
metallic  state,  forming  minute  malleable  beads. 

788.  ^Examination  of  the  solid  portion, — If  the  examina- 
tion  of  the   liquid   portion  should   fail  in   proving  the 
presence  of  lead,  the   poison   may  still  be  sought  for  in 
the  solid  or  semi-solid  matters  left  on  the  filter  (783), 
since  it  may  exist  in  combination  with  animal  matter,  or 
in  some  other  insoluble  form.    The  mixture  is  evaporated 
to  dryness,  and  the  dry  mass  incinerated  in  a  clean  fire- 
clay or  porcelain  crucible.     The  gray  ash  is  reduced  to 


DETECTION    OF    LEAD    IN    THE    TISSUES.       303 

powder  and  treated  with  boiling  water  as  long  as  a  drop 
of  the  washings  leaves  any  residue  when  evaporated  on  a 
slip  of  glass.  The  solution  thus  obtained  may  possibly 
contain  lead,  and  should  therefore  be  tested  with  sulphu- 
retted hydrogen  (784). 

789.  But  the  greater  part  of  the  metal  would  remain 
in  the  residue,  which  must  now  be  boiled  with  a  mixture 
of  equal  measures  of  nitric  acid  and  water  for  a  few 
minutes.     The  filtered  solution  is  examined  for  lead  as 
in  786. 

790.  The  residue  left  undissolved  by  nitric  acid  may 
still  contain  lead  in  the  form  of^ulphate:  by  boiling  it 
with  a  little  acetate  of  ammonia  (prepared  by  mixing 
ammonia  with  acetic  acid  in  slight  excess),  this  may  be 
extracted,  and  the  lead  detected  in  the  solution  by  hydro- 
sulphuric  acid.     It  may  still  be  advisable  to  dry  the 
residue,  mix  it  with  carbonate  of  soda  and  charcoal,  and 
fuse  it  at  a  bright  red  heat,  either  before  the  blowpipe, 
or  in  a  covered  crucible,  in  order  to  obtain  if  possible  a 
bead  of  metallic  lead. 

SECTION  III. 
Detection  of  Lead  in  the  Tissues. 

791.  When,  in  a  suspected  case  of  poisoning  by  lead, 
no  trace  of  the  metal  can  be  detected  in  the  contents  of 
the  stomach,  &c.,  it  is  necessary,  before  deciding  upon 
the  absence  of  the  poison,  to  examine  the  tissues  of  the 
stomach,  intestines,  and  especially  the  liver ;  since  it  may 
be  often  found  absorbed  in  these  tissues,  even  when  no 
trace  is  to  be  met  with  elsewhere. 

792.  The  portion  of  the  body  intended  for  examination 
is  to  be  cut  into  thin  slices,  dried,  incinerated  as  com- 
pletely as  possible  at  a  moderate  heat,  and  examined  as 
in  788—790. 


304:  DETECTION    OF    COPPER    IN 


CHAPTEK  V. 

COPPER. 

793.  LIKE  lead,  copper  is  not  often  employed  for  the 
purpose  of   criminally  destroying  life;  but  is  not  un- 
frequently  taken    accidentally,   dissolved    in    articles  of 
food,  with   serious,   and    sometimes  fatal    results.     The 
chief  cause    of  such   accidents    is    the   employment   of 
untinned   copper    vessels   for   culinary   purposes ;    and 
although  such  vessels,  when  perfectly  clean,  may  be  used 
in  the  preparation   of  certain  articles  of  food  without 
risk  of  impregnation,  still  the  number   of  alimentary 
substances  capable  of  acting  upon  and  dissolving  small 
quantities  of  the  metal,  is  so  great,  that  it  is  far  safer  to 
avoid  the  use  of  untinned  copper  vessels  in  all  culinary 
operations.     Acid  and  fatty  substances  especially,  and 
liquids  containing  common  salt  and  other  saline  matters 
in  solution,  should  never  be  boiled  in  such  vessels;  since 
the  quantity  of  copper  dissolved  by  them  is  sometimes 
so  considerable  as  to  impart  a  green  or  bluish  color  to 
the  mixture. 

SECTION  I. 

Detection  of  Copper  in  Organic  Mixtures. 

794.  Copper  may  exist  in  such  mixtures  either  in  a 
state  of  solution,  or  in  combination  with  certain  organic 
or  other  substances,  forming  compounds  which  are  more 
or  less  insoluble  in  water.     On  this  account,  when  the 
mixture  to  be  examined  consists  of  both  liquid  and  solid 
matters,  it  should  first  be  warmed  with  a  little  hydro- 
chloric or  acetic  acid,  by  which  means  the  copper  will  be 
brought  into  solution.     The  solution  may  then  be  filtered 
from  the  insoluble  portion,  which  latter  should  be  retained, 
in  case  it  may  be  required  for  subsequent  examination. 

795.  The  clear   liquid,  slightly  acidified  with   a  few 


ORGANIC    MIXTURES.  305 

drops  of  hydrochloric  acid,  is  now  to  be  tested  for  copper, 
by  placing  in  it  a  piece  of  clean  iron,  free  from  rust,  such 
as  a  needle  or  knife  blade.  If  copper  is  present  in  the 
liquid,  it  will  in  a  short  time  be  deposited  in  the  metal- 
lic state  on  the  surface  of  the  iron,  giving  it  all  the  ap- 
pearance of  copper ;  white  the  iron  is  at  the  same  time 
dissolved  in  atomic  proportion.  The  color  of  the  freshly- 
deposited  copper  is  so  peculiar  and  characteristic,  that  it 
can  hardly  be  mistaken  after  being  once  seen ;  so  that 
this  experiment  is  generally  sufficient  of  itself  to  prove 
the  presence  of  the  metal.  If,  however,  any  doubt  exists 
as  to  its  presence,  the  following  tests  may  be  applied, 
either  to  a  portion  of  the  liquid  from  which  the  copper 
has  not  been  removed  by  means  of  the  iron,  or  to  a  so- 
lution of  the  precipitated  copper,  scraped  off  the  iron,  in 
dilute  nitric  acid. 

796.  (a)  Hydrosulphuric  acid   and   hydrosulphate  of 
ammonia  throw  down  a  black  precipitate  of  sulphide  of 
copper  (CuS). 

(b)  Ammonia,  when  added  in  small  quantity,  throws 
down  a  pale  blue  precipitate,  which,  if  the  ammonia  be 
added  in  excess,  redissolves,  forming  a  beautiful  blue  so- 
lution. 

(c)  Potash  throws  down  in  the  cold  solution  a  pale  blue 
precipitate  of  hydrated  oxide  (CuO,HO) ;  which,  on  boil- 
ing the  mixture,  becomes  black,  owing  to  the  formation 
of  the  anhydrous  oxide  (CuO).     The  potash  must  here  be 
added   slightly  in  excess,  as  otherwise   the   precipitate 
would  consist  of  a  basic  salt,  which  would  not  become 
black  when  boiled. 

(d)  Ferrocyanide  of  potassium  causes,  even  in  very 
dilute  acid  or  neutral  solutions,  a  mahogany-colored  pre- 
cipitate of  ferrocyanide  of  copper  (Cu2,FeCy3),  which  is 
insoluble  in  dilute  acids. 

797.  In  case  no  copper  can  be  detected  in  the  liquid 
portion,  it  is  advisable,  before  deciding  that  the  metal  is 
altogether  absent,  to  examine  the  residue  which  proved 
insoluble  in  the  dilute  acid  (794).     For  this  purpose  it  is  to 
be  evaporated  tg  dryness,  and  ignited  in  a  covered  Ber- 
lin porcelain  crucible.     The  incinerated  residue  is  then 
warmed  with  a  little  dilute  nitric  acid,  which  will  dissolve 

26* 


306      DETECTION    OF    COPPER    IN    THE    TISSUES. 

any  traces  of  copper  that  may  be  present.  The  acid  solu- 
tion is  evaporated  nearly  to  dryness,  in  order  to  expel  most 
of  the  excess  of  acid,  and  filtered;  after  which  the  solu- 
tion may  be  tested  with  a  piece  of  clean  iron  (795),  and 
also,  if  necessary,  with  the  other  reagents  above  enume- 
rated (796). 

798.  When  the  solution  containing  copper,  even  in  the 
presence  of  much  organic  matter,  is  subjected  to  electro- 
lysis (753),  the  metal  is  deposited  upon  the  negative  plate, 
and  may  be  recognized  by  its  color,  and  by  the  appro- 
priate tests  (796)  applied  to  the  solution  obtained  by 
boiling  the  negative  plate  with  nitric  acid. 

SECTION  II. 
Detection  of  Copper  in  the  Tissues. 

799.  Like  the  other  metallic  poisons,  copper  is  readily 
absorbed    by  the  tissues,  where  it   may  frequently  be 
found  in  cases  where  no  trace  can  be  detected  in  the  con- 
tents of  the  stomach  and  intestines.     On  this  account,  it 
is  necessary,  before  concluding  that  no  copper  can  be 
found,  to  examine  the.liver  and  other  viscera,  which  may 
be  done  in  the  following  manner. 

800.  The  part  intended  for  examination  is  to  be  cut 
into  thin  slices,  and  treated  with  hydrochloric  acid  and 
chlorate  of  potash,  as  directed  in  761.     The  acid  solution, 
after    filtering,  is  evaporated   nearly  to  dryness;    after 
which  it  may  be  tested  with  a  piece  of  clean  iron  (795), 
and,  if  necessary,  by  paragraphs  796,  798. 

If  no  copper  can  be  detected  in  this  solution,  the  inso- 
luble organic  matter  may  be  incinerated  and  examined 
according  to  797. 

SECTION  III. 
Quantitative  Determination  of  Copper. 

801.  The  quantity  of  copper  present  in  any  organic 
mixture  may  be  ascertained  by  incinerating  the  dried 
organic  matter,  boiling  the  ash  with  dilute  nitric  acid, 
saturating  the  liquid  (after  filtering)  witfi  hydrosulphuric 
acid  gas,  which  will  throw  down  the  whole  of  the  copper 


ZINC.  307 

as  sulphide.  The  precipitate  is  to  be  dissolved  in  hot 
nitric  acid,  and  the  copper  thrown  down  as  oxide,  by 
supersaturating  the  hot  solution  of  the  nitrate  with  potash. 
The  black  oxide  thus  precipitated  is  to  be  washed  with 
a  large  quantity  of  hot  water,  filtered,  dried,  ignited,  and 
weighed.  From  the  weight  of  the  oxide,  that  of  the 
metallic  copper  may  be  calculated  as  follows : — 

Ate.  wt.  of  oxide         Ate.  wt.  of         Wt.  of  oxide         Wt.  of  copper  in  the  quantity 
of  copi>.>r.  iMpper.  obtained.  of  mixture  employed. 

~40~~        :  32 


CHAPTER  VI. 

ZINC. 

Detection  of  Zinc  in  Organic  Mixtures  and  in  the  Tissues. 

802.  ZINC  has  occasionally  to  be  looked  for  in  organic 
mixtures  and  in  the  tissues,  the  sulphate  being  often  ad- 
ministered as  an  antidote  in  cases  of  poisoning.     It  may 
be  detected  by  boiling  the  suspected  matters,  in  a  finely 
divided  state,  with  a  little  dilute  hydrochloric  acid  and 
chlorate  of  potash,  and  filtering,  if  necessary,  from  any 
insoluble  residue.    The  clear  solution  thus  obtained  may 
then  be  supersaturated  with  ammonia,  and  filtered,  after 
which  the  clear  ammoniacal  solution  may  be  tested  with 
a  current  of  hydrosulphuric  acid  gas  (sulphuretted  hy- 
drogen), which,  if  zinc  is  present,  will  throw  down   a 
white  precipitate  of  sulphide  (ZnS).     The  sulphide  thus 
formed  may  be  separated  from  the  liquid  by  filtration, 
and  dissolved  in  a  little  nitric  acid;  the  excess  of  acid 
employed  being  afterwards  expelled  by  evaporating  the 
solution  to  dryness.* 

803.  The  residue  should  be  boiled  with  water  and  a 

*  If  this  residue  is  carbonized  when  further  heated,  it  is  advisable 
to  continue  the  heat  as  long  as  any  vapors  are  evolved,  to  boil  the 
charred  mass  with  hydrochloric  acid,  and  to  evaporate  the  filtered 
liquid  to  dryness. 


308  ZINC. 

little  nitric  acid,  the  solution  filtered,  if  necessary,  and 
examined  by  the  following  tests : — 

(a)  Add  ammonia  in  excess ;  filter  the  solution  from 
any  precipitate  which  may  be  formed,  and  add  hydrosul- 
phate  of  ammonia :  if  zinc  be  present,  a  white  flaky  pre- 
cipitate of  sulphide  of  zinc  should  be  produced.* 

(b)  Add  ammonia  in  excess ;  filter,  if  necessary,  acidify 
the  filtered  liquid  with  acetic  acid,  and  add  ferrocyanide 
of  potassium  ;  a  white  precipitate  of  ferrocyanide  of  zinc 
should  be  obtained. 

(c)  Mix  the  remainder  of  the  solution  with  carbonate 
of  soda  in  slight   excess,  and  boil  for  a  few  minutes; 
collect  the  precipitate  (basic  carbonate  of  zinc)  upon  a 
filter,  wash  it,  and  incinerate  the  filter,  when  dry,  in  a 
small  porcelain   crucible.    If  zinc  be  present,  the  ash 
will  be  yellow  while  hot,  and  white  on  cooling.    Place  it 
in  a  small  cavity  on  a  piece  of  charcoal,  moisten  it  with 
nitrate  of  cobalt,  and  heat  strongly  before  the  blowpipe; 
a  green  mass  should  be  produced  if  zinc  be  present. 

804.  If  it  be  desired  to  examine  the  zinc  in  the  residue 
left  by  the  hydrochloric  acid  and  chlorate  of  potash  (802), 
it  must  be  washed,  dried;  and  calcined  at  a  low  red  heat 
in  an  open  crucible.  The  mass  may  then  be  boiled  with 
hydrochloric  acid,  the  filtered  solution  evaporated  to 
dryness  and  further  tested  as  directed  above  (803). 

• ' 

*  If  ammonia  had  not  previously  been  added  in  excess,  the  hydro- 
sulphate  of  ammonia  would  have  given  a  white  precipitate  of  sulphur, 
even  if  no  zinc  were  present ;  but  this  precipitate  would  simply  im- 
part a  milky  appearance  to  the  liquid  instead  of  separating  in  distinct 
flakes.  The  precipitate  of  sulphate  of  zinc  is  usually  dirty  white, 
from  the  presence  of  a  little  sulphide  of  iron. 


IODINE.  309 


CHAPTER  VII. 

IODINE. 


SECTION  I. 
Detection  of  Uncombined  Iodine  in  Organic  Mixtures,  &c. 

805.  WHEN  iodine  is  present  in  an  organic  mixture,  it 
may  be  detected  in  the  following  manner,  which  will  also 
serve  to  identify  it  after  having  been  absorbed  by  the 
tissues  of  the  stomach,  liver,  or  other  organ,  such  organ 
having  been  first  carefully  cut  into  thin  slices,  and  mace- 
rated with  a  little  water.     The  characteristic   smell  of 
iodine  is  generally  perceptible  in  liquids  containing  it ; 
and  it  usually  imparts  to  organic  mixtures  a  yellow  or 
greenish  color. 

806.  The  mixture  may  first  be  examined  for  any  par- 
ticles of  iodine  that  may  be  present  in  the  solid  state ; 
which,  if  found,  may  be  at  once  identified  as  such  by  the 
beautiful   violet-colored  vapor  which   they  form  when 
gently  heated  in  a  small  glass  tube.* 

807.  If  no  solid  iodine  can  be  found,  the  liquid  may 
be  tested  with  a  solution  of  starch;  or  a  strip  of  cotton 
or  paper,  impregnated  with  starch,  may  be  moistened 
with  it.     If  iodine  is  present  in  the  solution,  it  will  im- 
mediately strike  a  more  or  less  decided  purple  color,  the 
intensity  of  the  tint  varying  from  almost  black  to  a  pale 
shade  of  pink  or  lilac,  according  to  the  quantity  of  iodine 
dissolved  in  the  liquid. 

808.  Should  the  quantity  of  iodine  in  the  solution  be 
so  minute  as  to  fail  in  producing  a  sufficiently  decided 

*  Since  indigo  also  gives  violet  vapors,  the,  next  test  should  always 
be  applied. 


310  IODINE. 

result,  the  liquid  may  be  well  shaken  with  a  little  chlo- 
roform, which  will  dissolve  the  iodine  and  acquire  a 
beautiful  violet  color.  The  mixture  is  allowed  to  stand 
in  order  that  the  chloroform  may  collect  at  the  bottom 
of  the  vessel,  and  the  aqueous  liquid  is  drawn  off  by  a 
syphon  or  pipette.  The  chloroform  is  poured  into  a 
watch  glass,  and  allowed  to  evaporate  spontaneously, 
when  the  iodine  will  be  left,  and  may  be  recognized 
either  by  heating  it  in  a  tube  (806)  or  by  stirring  it  with 
water  and  adding  a  little  thin  starch  paste  (807). 

809.  If  the  iodine  be  present  in  the  solution  as  an 
iodide,  it  must  be  liberated  previously  to  the  application 
of  the  above  tests.  For  this  purpose  the  organic  mixture 
should  be  slightly  acidulated  with  hydrochloric  acid, 
heated  for  some  time  upon  a  water-bath,  and,  if  necessary, 
filtered.  The  cold  solution  is  then  mixed  with  a  little 
sesquichloride  of  iron,  to  which  enough  dilute  sulphuric 
acid  has  been  added  to  render  it  colorless,  and  agitated 
with  chloroform,  when  the  liberated  iodine  will  be  recog- 
nized as  in  808.  In  this  process  the  persalt  of  iron  is 
reduced  to  the  condition  of  a  protosalt,  by  imparting  an 
atom  of  oxygen  to  the  hydrogen  or  metal  in  combination 
with  the  iodine,  which  is  thus  set  free : — 

Iodide  Persulphate  Sulphate  Protosulphate 

potassium.  iron.  potash'.  iron. 


KI     +     Fe203,3S03    =     KO,S03    +   2(FeO,S03)  +  I. 
Chlorine  and  chloride  of  lime  are  sometimes  employed 
to  liberate  the  iodine,  but  it  is  not  easy  to  avoid  the 
addition  of  an  excess  which  converts  the  iodine  into 
chloride  of  iodine.* 

*  The  introduction  of  a  little  sulphuric  acid  and  a  piece  of  zinc, 
however,  will  restore  the  blue  color  when  destroyed  by  an  excess  of 
chlorine. 


SULPHURIC    ACID.  311 


CHAPTER  VIII. 

SULPHURIC  ACID  (IIO,SO.J. 

SECTION  I. 
Detection  of  Sulphuric  Acid  in  Organic  Mixtures. 

810.  SULPHURIC  acid  may  be  readily  detected,  even 
when  mixed  with  a  large  quantity  of  foreign  matter. 
Should  the  substance  to  be  examined  be  viscid  or  semi- 
solid,  it  may  be  diluted  with  a  little  water,  and  boiled ; 
after  which,  if  any  solid  matter  remains  in  suspension,  it 
may  be  filtered  through  muslin  or  paper. 

811.  If  the  liquid  contains  free  sulphuric  acid,  it  will  of 
course  strongly  redden  blue  litmus  paper. 

812.  Mix  the  liquid  to  be  tested  with  a  little  hydro- 
chloric acid,  and  add  a  solution  of  chloride  of  barium  or 
nitrate  of  baryta.     If  sulphuric  acid  is  present,  a  copious 
white  precipitate  of  sulphate  of  baryta  will  be  produced, 
which  will  not  dissolve  on  boiling  the  acidified  mixture, 
nor  yet  on  diluting  it  with  a  considerable  quantity  of 
water. 

813.  Since  traces  of  sulphuric  acid  may  be  contained 
in  the  nitric  acid  used  in  acidifying  the  mixture  (814),  a 
little  of  the  nitric  acid  employed  should  be  diluted  with 
three  or  four  times  its  bulk  of  water,  and  tested  with 
chloride  of  barium. 

814.  It   is  possible,   also,   that   the   substance   under 
examination  may  contain  some  soluble  sulphates  in  solu- 
tion, as  sulphate  of  magnesia,  sulphate  of  zinc,  &c.,  which 
would  cause  the  precipitation  of  sulphate  of  baryta  with 
chloride  of  barium,  even  when  no  free  sulphuric  acid  is 
present.     To  remove  this  source  of  error,  a  little  of  the 
suspected  fluid  may  be  evaporated  nearly  to  dry  ness  at  a 


312         DETECTION    OF    SULPHATE    OF    INDIGO. 

gentle  heat,  when  any  saline  matter  that  may  be  present 
will  crystallize  out ;  while  the  free  sulphuric  acid  will 
continue  liquid,  and  may  be  identified  by  the  proper 
tests. 

815.  It  is  not  often,  however,  that  any  serious  uncer- 
tainty can  exist  as  to  whether  the  sulphuric  acid  found 
mixed  with  organic  matter  was  or  was  not  uncombined, 
especially  in  cases  of  suspected    poisoning ;    since  the 
corrosive  effects  of  the  acid  upon  the  parts  with  which  it 
has  been  in  contact,  or  other  corroborative  circumstances, 
will  generally  of  themselves  furnish  evidence  sufficiently 
conclusive. 

816.  A  very  simple  and  delicate  test  for  free  sulphuric 
acid  consists  in  dipping  a  piece  of  white  linen  or  paper 
into  the  solution,  and  drying  it  before  the  fire.     As  the 
water  evaporates,  the  acid  will  carbonize  the  fabric.  Solu- 
tions containing  organic  matter  as  well  as  free  sulphuric 
acid  yield  a  carbonaceous  mass  when  evaporated  nearly 
to  dryness. 

SECTION  II. 
Detection  of  Sulphuric  Acid  in  Stains  on  Clothing. 

817.  The  stains  formed  by  sulphuric  acid  on  articles 
of  clothing  are   usually  moist  to  the   touch,   and  most 
commonly   of  a  brown  or  red  color,  varying,  however, 
with  the  nature  of  the  material  and  of  the  dye.     The 
acid  may  be  detected  in  them  by  boiling  the  stained  part 
with  water,  and  testing  the  solution  as  in  the  preceding 
section.* 

SECTION  III. 
Detection  of  Sulphate  of  Indigo  in  Organic  Mixtures ,  &c. 

818.  The  solution  of  indigo  in  sulphuric  acid,  com- 
monly called  sulphate  of  indigo,  which  is  occasionally 
either  employed  as  a  poison,  or  criminally  thrown  upon 
the  person,  may  be  detected  in  the  same  manner  as  the 
simple  acid.     It  has  a  deep  blue  color,   which  may  be 
destroyed  by  boiling  with  nitric  acid  previous  to  the 

*  When  the  stained  fabric  is  dried  before  the  fire,  it  becomes  charred 
where  the  acid  had  touched  it. 


HYDROCHLORIC    ACID.  313 

application  of  the  tests  ;  after  which  the  sulphuric  acid 
may  be  identified  either  in  organic  mixtures  or  on  articles 
of  clothing,  by  the  experiments  described  in  paragraphs 
812—817. 


CHAPTER  IX. 

HYDROCHLORIC    ACID  (HCl). 


SECTION   I. 
Detection  of  Hydrochloric  Acid  in  Organic  Mixtures. 

819.  WHEN  free  hydrochloric  acid  is   present  in  an 
organic  mixture,  it  may  be  detected  in  the  following 
manner.     If  solid  or  semi-solid  matter  is  mixed  with  the 
liquid,  it  should  be  first    boiled,  and   filtered   through 
muslin  ;  and  when  the  mixture  is  thick  and  viscid,  a  little 
water  should  be   mixed   with   it   before   boiling.     The 
liquid  is  then  treated  with  a  tolerably  strong  infusion  of 
galls,  as  long  as  it  causes  a  precipitate,  in  order  to  throw 
down  most  of  the  dissolved  animal  matter,  which  would 
otherwise  tend  to  prevent  the  acid  distilling  over.     The 
precipitate  is  then  separated  from  the  clear  liquid,  either 
by  again  filtering  through  muslin,  or  by  decantation. 

820.  A  few  drops  of  the  solution,  thus  purified  from 
the  greater  portion  of  the  organic  matter,  may  now  be 
tested  with  nitrate  of  silver.     If  this  causes  a  white  pre- 
cipitate, soluble  in  ammonia,  and  insoluble  in  nitric  acid, 
the  liquid  will  have  to  be  further  examined  (821);   since 
the  precipitate  may  be  owing  to  the  presence  of  chloride 
of  sodium  or  some  other  soluble   chloride.     But  if  no 
such   precipitate   is   occasioned  by  the  silver  salt,   the 
absence  of  hydrochloric  acid  may  be  relied  on ;  unless, 
indeed,  the  solution  is  ammoniacal,  in  which  case  it  should 
first  be  neutralized  or  slightly  supersaturated  with  nitrio 
acid. 

821.  In  order  to  prove  whether  the  precipitate  caused 
27 


314         DETECTION    OF    HYDROCHLORIC    ACID. 

by  nitrate  of  silver  is  owing  to  the  presence  of  free  hy- 
drochloric acid,  or  of  some  soluble  chloride,  the  liquid  is 
to  be  distilled  to  dryness  in  a  retort.  The  neck  of  the 
retort  is  to  be  attached  by  means  of  a  perforated  cork  to 
a  quilled  receiver,  the  quill  of  which  should  be  allowed 
to  dip  just  below  the  surface  of  a  little  pure  water  placed 
in  the  flask  or  bottle  intended  for  its  reception.  The  bulb 
of  the  retort  is  to  be  heated  in  a  chloride-of-calciumbath; 
the  heat  of  which  may  be  raised,  towards  the  end  of  the 
distillation,  to  about  230°. 

822.  When  the  whole  of  the  liquid  has  distilled  over, 
the  contents  of  the  receiver  are  to  be  examined,  first  with 
blue  litmus  paper,  which,  if  any  free  acid  is  present,  will 
become  reddened ;    and  also  with  nitrate  of  silver,  which 
will  give  a  copious  white  precipitate  of  chloride,  soluble 
in  ammonia,  and  insoluble  in  hot  nitric  acid,  in  case  any 
free  hydrochloric  acid  was  present  in  the  mixture,  since 
such  acid  would  distil  over  with  the  water. 

823.  A  little  of  the  distilled  liquid  may  also  be  mixed 
with  a  few  drops  of  pure  nitric  acid,  and  boiled  for  a  few 
minutes  with  a  small  fragment  of  gold  leaf.     If  the  latter 
dissolves,  it  is  an  additional  proof  that  the  acid  is  hydro- 
chloric. 

824.  In  examining  the  contents  of  a  stomach,  it  must 
be  borne  in  mind  that  minute  quantities  of  free  hydro- 
chloric acid  are  probably  always  present  as  one  of  the 
normal  constituents  of  the  gastric  juice  ;   so  that  the  dis- 
tilled liquid  may  always  be  expected  to  contain  some 
traces  of  it.     The  amount  of  the  acid  derived  from  this 
source  is,  however,  so  small,  that  it  may  readily  be  dis- 
tinguished from  the  comparatively  large  quantity  usually 
to  be  found  when  the  acid  has  been  swallowed.* 

SECTION  II. 
Quantitative  Determination  of  Hydrochloric  Acid. 

825.  The  chloride  of  silver  ( AgCl)  obtained  by  adding 
nitrate  of  silver  to  the  distilled  acid  liquid  (822),  is  to  be 

*  It  must  be  remembered  that  free  hydrochloric  acid  would  distil 
over  from  mixtures  containing  chlorides  together  with  free  sulphuric, 
phosphoric,  oxalic,  or  lactic  acid. 


NITRIC    ACID.  315 

washed  on  a  filter,  dried,  and  heated  to  dull  redness  in  a 
counterpoised  porcelain  crucible,  until  it  begins  to  fuse. 
From  the  weight  of  the  chloride  thus  obtained,  that  of  the 
hydrochloric  acid  present  in  the  mixture  may  be  calcu- 
lated as  follows  :  — 


143-5       :  36-5 


CHAPTER  X. 

NITRIC   ACID  (HO,NO^. 


SECTION  I. 
Detection  of  Nitric  Acid  in  Organic  Mixtures. 

826.  IF   any   solid  or  semi-solid    organic   matter   is 
present  in  the  mixture,  it  should  be  separated  by  filter- 
ing  through  muslin,  having  first  heated  it  on  a  water- 
bath  in  order  to  effect  a  separation  of  the  greater  part  of 
the  acid  present,  from  the  solid  matters  which  may  be 
more  or  less  impregnated  with  it.     Should  the  liquid  be 
thick  and  viscid,  it  may  be  first  diluted  with  a  little  water. 

827.  If  free  nitric  acid  is  present  in  any  considerable 
quantity  in  the  liquid,  it  will  probably  be  recognized  by 
its  peculiar  smell ;    and  the  characteristic  yellow  stain  of 
the  tissues  with  which  it  has  been  in  contact  is  in  most 
cases  perceptible.     The  want  of  smell,  however,  is    no 
proof  of  the  absence  of  the  acid ;    which  may  still  be 
present  in  considerable  quantity,  either  diluted  with  a 
comparatively  large  amount  of  liquid,  or  even  more  or 
less  completely  neutralized  by  magnesia,  or  some  other 
alkaline  substance  that  may  have  been  administered  as  an 
antidote.     In  the  latter  case,  the  liquid  may  be  neutral, 
or  nearly  so,  to  test  paper. 

828.  In  order  to  detect  nitric  acid,  the  liquid,  after  fil- 


316         NITRIC   ACID    IN    ORGANIC    MIXTURES. 

tration,  may,  if  acid,  be  neutralized  with  carbonate  of 
potash,  and  evaporated  to  dryness  at  a  gentle  heat.  The 
nitric  acid  will  thus  be  obtained  in  combination  with 
potash,  forming  nitrate  of  potash,  which  will  be  deposited 
in  needle-shaped  crystals  when  most  of  the  water  is  ex- 
pelled; unless,  indeed,  the  crystallization  is  prevented 
by  the  admixture  of  much  animal  or  other  matters. 

829.  The  greater  part  of  the  saline  residue  thus  ob- 
tained, is  to  be  dissolved  in  as  small  a  quantity  of  water 
as  possible,  and  the  solution  placed  in  four  test-tubes,  for 
the  following  experiments : —  • 

(a)  The  first  portion  is  mixed  in  a  small  test  tube,  with 
a  few  drops  of  strong  sulphuric  acid ;  after  which  a  clean 
strip  or  two  of  copper,  or  a  little  roll  of  copper  wire,  is 
dropped  in,  and,  if  necessary,  a  gentle  heat  applied.    If 
nitric  acid  is  present,  orange  fumes  of  nitrous  acid  will 
be  given  offj  the  smell  of  which  may  generally  be  recog- 
nized, even  when  in  too  small  quantity  to  be  apparent 
to  the  eye. 

(b)  To  the  second  portion  add  a  few  drops  of  hydro- 
chloric acid,  and  put  a  small  fragment  or  two  of  gold 
leaf  into  the  mixture.     If  nitric  acid  is  present,  the  gold 
leaf  will  be  partially  or  wholly  dissolved ;  and  the  pre- 
sence of  gold  in  the  solution  may  be  proved  by  proto- 
chloride  of  tin  causing  with  it  a  purple  precipitate. 

(c)  The  third  portion  is  to  be  acidified  with  a  few  drops 
of  strong  sulphuric  acid,  and  as  soon  as  the  mixture  is 
cool,  a  small  crystal  of  protosulphate  of  iron  is  dropped 
in;  when,  if  nitric  acid  is  present,  the  liquid  round  the 
crystal  will  assume  a  brown  color,  which  disappears  on 
boiling  the  mixture. 

(d)  Mix  the  remaining  portion  of  the  solution  with 
sulphuric  acid,  and  add  a  drop  of  dilute  sulphate  of  in- 
digo, sufficient  to  give  the  liquid  a  pale  blue  color.     If 
nitric  acid  is  present,  the  color  of  the  indigo  will  disap- 
pear, especially  on  warming  the  mixture. 


OXALIC    ACID.  317 

SECTION  II. 
Detection  of  Nitric  Acid  in  Stains  on  Clothing. 

830.  Stains  occasioned  by  the  action  of  nitric  acid  on 
woollen  cloth  are  usually  of  a  brown  or  yellowish  color, 
and,  unlike  those  caused  by  sulphuric  acid  (817),  become 
in  a  short  time  dry  and  extremely  rotten.  The  yellow 
color  of  the  nitric  acid  stain  is  changed  to  orange  by  pot- 
ash or  ammonia,  which  will  generally  restore  the  original 
color  of  fabrics  stained  by  hydrochloric  or  sulphuric  acid. 
If  recent,  the  acid  may  generally  be  detected  in  them, 
by  boiling  the  stained  part  with  a  little  water,  neutral- 
izing with  potash,  and  applying  the  tests  mentioned  in 
paragraph  829,  but  if  any  considerable  time  has  elapsed 
since  the  production  of  the  stain,  it  is  probable  that  all 
traces  of  the  acid  will  have  disappeared,  partly  by  eva- 
poration, and  partly  by  decomposition,  occasioned  by 
contact  with  the  organic  matter. 


CHAPTER  XL 

OXALIC  ACID  (HO,C203,) 


SECTION  I. 
Detection  of  Oxalic  Acid  in  Organic  Mixtures. 

831.  BEFORE  proceeding  to  apply  the  several  tests  for 
oxalic  acid  in  the  contents  of  a  stomach,  vomited  matters, 
or  other  mixtures  containing  organic  matter,  it  is  ad- 
visable first  to  separate  the  latter,  since  its  presence 
might  interfere  with  the  action  of  some  of  the  reagents.* 
If  lime  or  magnesia  has  been  used  as  an  antidote,  the 
oxalic  acid,  if  present,  will  be  either  wholly  or  in  part 
in  the  form  of  an  insoluble  oxalate ;  so  that,  in  that  case, 

*  Separation  by  dialysis  will  be  found  of  the  greatest  use  in  the 
case  of  oxalic  acid. 

27* 


318        OXALIC    ACID    IN    ORGANIC    MIXTURES. 

it  is  necessary  to  boil  the  sediment  with  a  solution  of 
carbonate  of  potash,  whereby  the  acid  will  be  brought 
into  solution  as  oxalate  of  potash  (7T0,(7203);  an  insolu- 
ble carbonate  of  the  earth  being  at  the  same  time  formed. 
CaO,C203  +  KO,C02  =  KO,C203  +  CaO,C02. 

832.  The  suspected  mixture  is  first  boiled,  to  insure 
the  solution  of  the  whole  of  the  acid  contained  in  it,  and 
filtered,  if  necessary,  from  any  solid  residue.    A  solution 
of  acetate  of  lead  is  then  added  as  long  as  it  causes  any 
precipitate,  which  will  throw  down  the  oxalic  acid  in  the 
form  of  the  insoluble  oxalate  of  lead  (PbO,C2O3),  together 
with  the  greater  part  of  the  soluble  organic  matter.     The 
precipitate  thus  formed  is  digested  for  an  hour  or  two  in 
dilute  hydrosulphate  of  ammonia,  and  the  mixture  then 
evaporated  to  dryness  on  a  water-bath.     The  lead  is  in 
this  way  separated,  in  the  form  of  the  insoluble  black 
sulphide,  from  the  acid;  which,  in  combination  with  the 
ammonia  (oxalate  of  ammonia),  may  be  dissolved  out 
with  water,  leaving  the  sulphide  undissolved,  together 
with  the  greater  part  of  the  organic  matter. 

833.  The  solution  thus  obtained  is  then  filtered,  and 
examined  in  the  following  manner  for  oxalic  acid: — 

(a)  A  solution  of  sulphate  of  lime,  or  a  very  dilute 
solution  of  chloride  of  calcium,  added  to  a  portion  of  the 
solution,  gives,  if  any  oxalic  acid  is  present,  an  immediate 
white  precipitate  of  oxalate  of  lime  (CaO,C2O34-2Aq), 
which  readily  dissolves  in  dilute  nitric  or  hydrochloric 
acid,  but  is  insoluble  in  acetic  or  tartaric  acid. 

(b)  If  the  oxalate  of  lime  formed  in  a,  be  gently  ig- 
nited on  platinum  foil,  it  will  be  converted  into  carbonate, 
with  little  or  no  blackening.    The  carbonate  of  lime  thus 
produced  will  be  found  to  effervesce  when  treated  with 
dilute  hydrochloric  acid,  and  if  a  little  of  it  be  strongly 
ignited  for  a  short  time,  it  will  be  still  further  decom- 
posed, and  the  carbonic  acrd  expelled ;  after  which  the 
residue  of  caustic  lime  will,  when  placed  on  a  piece  of 
moistened   turmeric   paper,  change  the  yellow  color  to 
brown. 

(c)  Test  another  portion  of  the  solution  with  nitrate  of 
silver.     If  oxalic  acid  is  present,  a  white  precipitate  of 


HYDROCYANIC   ACID.  319 

oxalate  of  pilver  (AgO,C203)  will  be  produced,  which  is 
soluble  both  in  nitric  acid  and  ammonia.  If  the  preci- 
pitate bo  dried,  and  gently  heated  on  platinum  foil,  it 
will  be  decomposed  with  a  slight  puff,  leaving  a  residue 
of  metallic  silver. 

SECTION  II. 
Quantitative  Determination  of  Oxalic  Acid. 

834.  The  quantity  of  oxalic  acid  in  the  liquid  may  be 
estimated  in  the  following  manner.     The  solution  is  first 
acidified  with  a  little  acetic  acid,  in  order  to  decompose 
any  soluble  carbonate  that  may  be  present.     A  solution 
of  chloride  of  calcium  is  then  to  be  added  as  long  as  it 
causes  any  precipitate ;  and  the  mixture  is  boiled  and  fil- 
tered.    The  precipitate,  after  being  washed  on  the  filter, 
is  dried,  and  gently  ignited  in  a  counterpoised  crucible. 
It  is  then,  after  cooling,  moistened  with  a  solution  of  car- 
bonate of  ammonia,  and  again  heated  a  little  below  red- 
ness, in  order  to  expel  the  excess  of  the  ammoniacal  salt, 
which  was  added  for  the  purpose  of  supplying  carbonic 
acid  to  any  lime  that  may  have  been  rendered  caustic  dur- 
ing the  first  ignition  (833&). 

835.  The  oxalate  of  lime  is  thus  wholly  converted  into 
carbonate ;  which  is  to  be  weighed,  and  from  its  weight 
that  of  the  oxalic  acid  may  be  calculated  as  follows : — 


Ate.  wt.  of  car-        Atl"  ,."'.  "',        Wt.  of  carb.  lime 

liquid  employed. 

50  63         ::        ~~a~ 


CHAPTER  XII. 

HYDROCYANIC  (OR  PRUSSIC)  ACID  (HCy). 

836.  THE  presence  of  hydrocyanic  acid,  even  when 
largely  diluted,  may  usually  be  detected  by  its  peculiar 
and  characteristic  odor,  somewhat  resembling  that  of  oil 
of  bitter  almonds.  Great  caution  is  necessary  not  to 


320  HYDROCYANIC    ACID. 

inhale  more  than  the  smallest  quantity  of^the  vapor, 
since  headache  and  other  unpleasant  symptoms  may  be 
occasioned  by  merely  smelling  it,  even  when  in  a  highly 
diluted  state. 

837.  It  must  be  remembered,  in  cases  of  suspected 
poisoning  with  this  acid,  that  no  time  should  be  lost  in 
applying  the  tests  for  its  presence;  since  it  rapidly  vola- 
tilizes, and,  unless  carefully  protected  from  the  air,  dis- 
appears entirely  in  the  course  of  a  few  days.     The  faci- 
lity with  which  the  acid  is  decomposed  when  in  contact 
with  putrefying  organic  matter  also  prevents  its  detection 
after  some  time  has  elapsed. 

SECTION  I. 

Detection  of  Hydrocyanic  Acid  in  Organic  Mixtures. 
I.   Detection  of  the  acid  in  the  state  of  vapor. 

838.  Very  small  traces  of  the  acid  may  be  detected  by 
one  or  other  of  the  following  tests,  which  may  be  readily 
applied  to  any  liquid  or  mixture  suspected  to  contain  it. 
There  is  also  this  advantage  in  being  able  to  identify  it 
without  going  through  the  process  of  distillation  at  a 
higher  temperature,  viz.,   that  while   the  tests  for  the 
vapor  which  I  am  about  to  describe  are  equally,  or  even 
more  delicate  than  those  for  the  liquid  after  distillation, 
the  chances  in  favor  of  the  spontaneous  formation  of  the 
acid  by  the  decomposition  of  the  organic  matter   are 
greatly  diminished. 

839.  A  little  of  the  mixture  suspected  to  contain  the 
poison,   slightly  acidified,  if  neutral    or   alkaline,   with 
dilute  sulphuric  acid,  may  be  placed  in  a  watch-glass,* 
over  which  another  similar  watch-glass  is  to  be  inverted, 
having  been  previously  moistened  with  a  drop  or  two  of 
a  solution  of  nitrate  of  silver,  care  being  taken  that  none 
of  the  latter  is  allowed  to  run  into  the  lower  glass.     The 

*  Since,  in  medico-legal  investigations,  it  is  not  desirable  to  trans- 
fer the  liquid  from  one  vessel  to  another  if  it  can  be  avoided,  it  is 
better  to  invert  the  watch-glasses  moistened  with  the  reagents  over 
the  mouth  of  the  bottle  in  which  the  contents  of  the  stomach,  &c., 
have  been  placed  as  soon  as  removed  from  the  body.  Of  course, 
pieces  of  glass  might  be  used  instead  of  wat^h-glasses. 


DETECTION    OF    HYDROCYANIC    ACID.          321 

glass  containing  the  suspected  solution  is  then  very  gently 
warmed  by  holding  it  in  the  hand ;  when,  if  any  hydro- 
cyanic acid  is  present,  it  will  volatilize  into  the  upper 
glass;  where,  on  coming  in  contact  with  the  silver  solu- 
tion, it  will  form  a  white  film  of  cyanide  of  silver  (AgCy). 
This  test  is  very  delicate :  but  as  a  somewhat  similar 
effect  might  be  produced  by  hydrochloric  acid,  it  is 
always  advisable  to  confirm  the  result  by  the  following 
experiments: — 

840.  A  little  of  the   suspected   mixture,  previously 
acidified,  if  necessary,  with  a  little  dilute  sulphuric  acid, 
is  put  into  a  watch-glass,  over  which  is  placed  another 
glass  moistened  with  a  drop  or  two  of  solution  of  potash. 
The  hydrocyanic  acid,  if  present,  gradually  evaporates 
into  the  upper  glass,  where  it  combines  with  the  potash, 
forming  in  solution  a  little  cyanide  of  potassium.     This 
is  then  mixed,  first  with  a  drop  of  a  solution  of  protosul- 
phate  of  iron  (which  should  have  been  exposed  to  the  air 
for  a  short  time,  so  as  to  have  become  partially  converted 
into  the  persulphate),*  and  afterwards  with  a  drop  or  two 
of  dilute  hydrochloric  acid,  which  should  be  added  in 
slight  excess.     Should  any  hydrocyanic  acid  have  been 
present  in  the  mixture,  a  blue  precipitate  of  Prussian 
blue  will  be  immediately  formed,  the  appearance  of  which 
may  be  considered  as  a  sure  proof  of  the  existence  of 
the  acid.  This  experiment  is  commonly  known  as  Scheelds, 
or  the  iron  test. 

If  the  hydrocyanic  acid  be  present  in  small  quantity, 
no  precipitate  of  Prussian  blue  will  be  seen  at  first,  but 
a  green  liquid  will  be  formed  which  will  deposit  flakes 
of  Prussian  blue  on  standing.  It  is  always  desirable  to 
compare  the  result  with  that  obtained  by  mixing  together 
in  another  watch-glass,  the  potash,  iron-salts,  and  hydro- 
chloric acid  in  the  same  proportions  as  were  employed 
in  the  test. 

841.  The  following  test,  commonly  known  as  Liebig's 
test,  which  is  perhaps  the  most  delicate  of  all,  may  also  be 
applied.  A  little  of  the  suspected  fluid  slightly  acidified,  if 

*  Or  a  drop  of  perchloride  of  iron  may  be  added  as  well  as  the  pro- 
tosulpliate. 


322  HYDROCYANIC    ACID. 

necessary,  is  put  into  a  watch-glass  as  before,  and  over 
this  another  watch-glass  is  inverted,  containing  a  drop 
of  hydrosulphate  of  ammonia,  which  for  this  purpose 
should  contain  an  excess  of  sulphur,  and  consequently 
have  a  yellow  color.  The  glasses  may  be  allowed  to 
remain  together  for  about  a  quarter  or  half  an  hour; 
after  which  the  upper  one  is  removed,  and  placed  on  a 
water-bath,  until  the  hydrosulphate  of  ammonia  is  eva- 
porated to  dryness.  Should  any  hydrocyanic  acid  have 
been  present  in  the  liquid,  some  of  its  vapor  will  have 
combined  with  the  hydrosulphate,  with  which  it  would 
form  sulphocyanide  of  ammonium.  The  residue  left 
after  the  evaporation  of  the  drop  is  now  to  be  moistened 
with  a  dilute  solution  of  persulphate  or  perchloride  of 
iron;  which,  in  case  any  sulphocyanide  of  ammonium 
had  been  formed,  or,  in  other  words,  in  case  any  hydro- 
cyanic acid  had  been  present  in  the  suspected  mixture, 
will  immediately  produce  a  blood-red  color,  owing  to  the 
formation  of  sulphocyanide  of  iron.  This  color  is  bleached 
by  perchloride  of  mercury  (corrosive  sublimate),  and  is 
thus  distinguished  from  that  caused  by  acetate  or  mecon- 
ate  of  iron. 

II.   Detection  of  Hydrocyanic  Acid  in  Solution. 

842.  The  mixture  suspected  to  contain  the  poison  is  to 
be  distilled  in  a  retort  heated  on  a  water-bath,  the  re- 
ceiver being  kept  cool  by  immersion  in  cold  water,  or 
in  a  freezing  mixture  composed  of  ice  and  salt,  or  of 
equal  weights  of  nitrate  of  ammonia  and  water.     When 
about  one-eighth  part  of  the  liquid  has  passed  over  into 
the  receiver,  the  distillation   may  be  stopped.     Should 
the  mixture,  previous  to  distillation,  be  neutral,  or  at  all 
alkaline  to  test  paper,  it  should  be  slightly  acidified  with 
dilute  sulphuric  acid,  in  order  to  disengage  the  hydro- 
cyanic acid  from  the  ammonia,  or  other  bases  which  may 
be  present,  and  which  would  tend  to  prevent  the  distil- 
lation of  the  acid  at  the  low  temperature   employed. 
The  presence  of  hydrocyanic  acid  in  the  distilled  liquid 
may  be  ascertained  by  the  following  peculiarities : — 

843.  Unless  the  quantity  of  acid  be  very  minute,  the 


DETECTION    OF    II  V  I)  HOC  VAN  1C    ACID.  323 

peculiar  odor,  resembling  that  of  oil  of  bitter  almonds, 
will  probably  be  apparent. 

84-1.  Test  a  little  of  the  distilled  liquid  with  a  solution 
of  nitrate  of  silver.  If  hydrocyanic  acid  is  present,  a 
white  precipitate  of  cyanide  of  silver  is  produced,  which 
is  soluble  in  ammonia  and  in  hot  nitric  acid,  but  insoluble 
in  the  cold  acid. 

845.  The  cyanide  of  silver  should  be  collected  upon  a 
filter,  washed  as  long  as  the  washings  are  acid,  and  dried 
at  a  gentle  heat.  It  is  then  to  be  subjected  to  the  follow- 
ing tests : — 

846.*  Place  a  very  small  fragment  of  iodine  at  the 
bottom  of  a  small  tube  closed  at  one  end,  and  above  it 
as  much  as  can  be  spared  of  the  supposed  cyanide  of  sil- 
ver. Apply  a  very  gentle  heat,  by  holding  the  tube  at 
some  distance  above  a  flame,  when  iodide  of  cyanogen 
will  be  formed,  and  will  condense  on  the  cool  part  of  the 
tube  in  very  fine  white  needles. 

AgCy  +  I2  =  Agl  +  Cyl. 

(If  a  very  little  cyanide  of  silver  be  used,  it  is  well  to 
cover  it  with  a  layer  of  carbonate  of  soda,  to  retain  any 
excess  of  iodine.) 

847.  File  off  that  portion  of  the  tube  which  contains 
the  sublimate,  and  warm  it  in  a  test  tube,  with  a  little 
dilute  yellow  hydrosulphate  of  ammonia  in  which  it  will 
dissolve.     Evaporate  the  solution  on  the  water-bath,  and 
test  the  residue  with  perchloride  of  iron  (841). 

If  a  sufficient  quantity  of  the  cyanide  of  silver  can  be 
obtained,  another  sublimate  of  iodide  of  cyanogen  may 
be  made  and  tested  by  dissolving  in  potash  and  applying 
the  Prussian  blue  test  (840). 

848.  Boil  a  little  of  the  cyanide  of  silver  with  yellow 
hydrosulphate  of  ammonia,  filter,  evaporate  on  a  water- 
bath,  and  apply  Liebig's  test  (841).     A  very  small  par- 
ticle of  cyanide  of  silver  may  be  tested  in  a  watch-glass, 
by  moistening  with  a  drop  of  yellow  sulphide  of  ammo- 
nium, evaporating  on   the  water-bath,  and  testing  with 
perchloride  of  iron. 

*  For  this  excellent  test  we  are  indebted  to  MM.  Henry  and  Hum- 
bert. 


324  HYDROCYANIC    ACID. 

849.  Add  to  a  little  of  the  distilled  liquid  in  a  test 
tube,  first  a  little  solution  of  potash;  then  a  drop  or  two 
of  a  solution   of  protosulphate  of  iron,  containing  also 
a  little  persulphate  (840);  and  lastly,  a  slight  excess  of 
dilute  hydrochloric  acid.     If  the  liquid  contains  hydro- 
cyanic acid,  a  precipitate  of  Prussian  blue  will  be  imme- 
diately produced ;  or  if  only  a  small  trace  is  present,  a 
few  hours  may  elapse  before  it  becomes  apparent. 

850.  Mix  another  .portion  of  the  distilled  liquid  with 
a  few  drops  of  yellow  hydrosulphate  of  ammonia,  evapo- 
rate the  mixture  to  dryness  on  a  water-bath,  and  test  as 
in  841. 

851.  The  evaporation  to  dryness  in  this  experiment  is 
necessary,  in  order  to  expel  the  excess  of  hydrosulphate 
of  ammonia;  which  would  otherwise  form  with  the  iron 
solution  a  black  precipitate  of  sulphide,  and  thus  obscure 
the  appearance  of  the  characteristic  red  color.*     During 
the  evaporation  the  heat  must  be  kept  very  moderate, 
lest  any  of  the  sulphocyanide  of  ammonium  that  may  be 
formed  by  the  action  of  the  hydrocyanic  acid  on  the  hy- 
drosulphate should  be  decomposed. 

SECTION  II. 
Quantitative  Determination  of  Hydrocyanic  Acid. 

852.  The  quantity  of  hydrocyanic  acid  contained  in  an 
organic  mixture  may  be  ascertained  with  sufficient  accu- 
racy for  most  purposes  by  distilling  the  acid  (842),  and 
precipitating  the  distilled  liquid  by  means  of  nitrate  of 
silver.     The  precipitated  cyanide  of  silver  is  washed  and 
dried  in  a  hot  water  oven  until  it  ceases  to  lose  weight. 
From   the  weight  of  the  cyanide  thus  obtained,  that  of 
the  anhydrous  hydrocyanic  acid  (HCy)  may  be  calculated 
as  follows: — 

Ate.  wt.  Ate.  wt.  of        Wt.  of  cyanide         Wt.  of  hydrocyanic 

of  cyanide        hydrocyanic  of  silver  acid  in  the  quantity 

of  silver.  acid.  obtained.  of  mixture  employed. 

~"l34        :     "~27        ::          T~        :  ~T 

*  Which  may  still  be  rendered  evident  by  filtering  the  liquid. 


OPIUM.  825 


CHAPTER  XIII. 

OPIUM. 

853.  OF  the  several  compounds  contained  in,  and  pe- 
culiar to  opium,  two  only,  morphia  (G34H19N06)  and  me- 
conic  acid  (3HO,C14IIOn),  are  possessed  of  sufficiently 
characteristic  properties  to  enable  us  to  identify  them 
when  mixed  with  other  matters ;  the  tests  for  these  sub- 
stances, moreover,  are  not  particularly  delicate,  so  that 
it  is  difficult,  and  not  unfrequently  impossible,  to  detect 
small  traces  of  them.     In  cases  of  poisoning  with  opium 
it  is  seldom  that  any  traces  of  it  can  be  found  in  the 
contents  of  the  stomach ;  so  that  the  tissues  of  the  sto- 
mach itself,  the  intestines,  and  also  any  vomited  matters, 
ought  to  be  carefully  examined  for  the  poison. 

Detection  of  Opium  in  Organic  Mixtures,  Tissues,  &c. 

854.  If  the  substance  to  be  examined  is  liquid  or  semi- 
fluid, it  should  first  be  evaporated  to  dryness,  or  nearly 
so,  on  a  water-bath.     If  solid,  the  suspected  substance 
may  be  cut  into  thin  slices.    The  residue  left  after  evapo- 
ration, or  the  sliced  solid  matter,  as  the  case  may  be,  is 
then  to  be  digested  for  an  hour  or  two,  with  the  aid  of  a 
gentle  heat,  in  a  flask  or  dish  placed  on  a  water-bath, 
with  a  small  quantity  of  water  containing  a  little  acetic 
acid.     The  mixture  is  filtered,  and  the  clear  liquid,  con- 
taining a  slight  excess  of  acetic  acid,^  is  treated  with  a 
solution  of  acetate  of  lead  (Pb  0,  G4ff3  03)  as  long  as  any 
precipitate  is  produced.     The  meconic  acid,  if  present,  is 
thus  thrown  down  in  combination  with  oxide  of  lead, 
forming  meconate  of  lead  (3PbO,G14IIO11) ;  while  the  mor- 
phia remains  in  solution  in  combination  with  acetic  acid 
(acetate  of  morphia),  together  with  any  excess  of  acetate 
of  lead  that  may  have  been  employed.     The  mixture  is 

28 


326  MORPHIA. 

warmed  (not  boiled,  since  by  boiling  some  of  the  meconic 
acid  might  become  decomposed)  and,  when  again  cold,  is 
filtered. 

855.  The  clear   solution  may  first  be  examined  for 
morphia ;  reserving  the  precipitate  for  subsequent  exa- 
mination. 

856.  A  current  of  hydrosulphuric  acid  (sulphuretted 
hydrogen)  is  passed  through  the  solution',  until  the  latter 
smells  distinctly  of  the  gas,  in  order  to  decompose  the 
excess  of  acetate  of  lead.     The  precipitated  sulphide  of 
lead  is  separated  by  filtration  from  the  solution ;  which 
latter,  after  boiling,  and  if  necessary  concentrated  by 
evaporation,  is  to  be  examined  for  morphia  by  means  of 
the  following  tests: — 

857.  Place  a  drop  or  two  of  the  concentrated  solution 
on  a  strip  of  glass,  and  add  a  drop  of  ammonia.     The 
morphia  will  be  precipitated  in  the  form  of  minute  needle- 
shaped  crystals,  which  may  .be  examined  under  the  mi- 
croscope. 

858.  Mix  a  small  quantity  of  the  solution  in  a  test- 
tube  or  watch-glass,  with   enough  solution  of  carbonate 
of  soda  to  give  it  a  decided  alkaline  reaction,  and  stir  the 
mixture  with  a  glass  rod,  rubbing  the  sides  of  the  vessel. 
A  crystalline  precipitate  of  morphia  will   be  deposited 
on  standing,  especially  upon  the  lines  of  friction.    Should 
the  carbonate  of  soda  produce  an  immediate  flocculent 
precipitate  (of  the  phosphate  or  carbonate  of  lime,  for 
example),  this  should  be  filtered  off'  immediately,  before 
the  solution  is  stirred  with  the  glass  rod,  and  should  be 
reserved  for  further  examination. 

859.  If  any  crystalline  precipitate  has  been  produced  by 
the  carbonate  of  soda,  it  must  be  collected  upon  a  small 
filter  (reserving  the  filtered  liquid)  and  washed  with  very 
small  quantities  of  cold  water  as  long  as  the  washings 
are  decidedly  alkaline  (these  washings  are  to  be  mixed 
with  the  filtered   liquid).     The   filter  is  then  carefully 
spread  out  upon  a  glass  plate,  and  a  drop  of  solution  of 
perchloride  of  iron  placed,  with  a  glass  rod,  upon  a  part 
of  the  precipitate;  if  morphia  be  present,  an  indigo-blue 
color  will  be  produced.     Another  particle  of  the  precipi- 


MORPHIA.  327 

tate  may  be  touched  with  a  drop  of  a  strong  nitric  acid, 
which  tinges  morphia  of  an  orange  red  color.* 

860.  The  solutionf  in  which  carbonate  of  soda  has  not 
caused  any  crystalline  precipitate,  or  which  has  been  fil- 
tered from  the  precipitate,  is  now  evaporated  to  dryness 
on  a  water-bath,  and  heated  with  alcohol,  which  would 
dissolve  the  morphia;  on  filtering  the  solution  and  evapo- 
rating to  dryness  on  the  water-bath,  the  morphia  will  be 
left,  and  may  be  tested  as  in  859. 

861.  The  flocculent  precipitate  produced  by  carbonate 
of  soda  (858)  may  be  examined  by  washing  it  with  a 
little  hot  alcohol  to  dissolve  the  morphia  which  may  then 
be  separated  by  evaporation  and  tested  as  in  859. 

862.  The  precipitate,  supposed  to  contain  meconate  of 
lead  (854),  is  now  to  be  mixed  with  water  in  a  beaker 
glass ;  and  while  suspended  in  the  liquid,  treated  with  a 
current  of  hydrosulphuric  acid,  the  mixture  being  stirred 
occasionally.     The  meconate  of  lead  is  thus  decomposed ; 
the  black  sulphide  of  lead  being  precipitated,  while  the 
meconic  acid,  if  present,  remains  in  solution.     The  mix- 
ture is  filtered  to  separate  the  sulphide  of  lead,  and  the 
clear  liquid  is  gently  warmed  (not  boiled  (854),)  in  order 
to  expel  the  excess  of  hydrosulphuric  acid  ;  and,  if  neces- 
sary, concentrated  by  evaporation  on  a  water-bath.    The 
meconic  acid,  if  present  in  sufficient  quantity,  may  then 
be  detected  by  the  following  tests: — 

863.  A  solution  of  perchloride  of  iron  gives  the  liquid, 
in  case  meconic  acid  is  present,  a  bright  red  color,  owing 
to  the  formation  of  meconate  of  iron.     The  color  closely 
resembles  that  caused  in  solutions  of  iron  by  the  sulpho- 
cyanides,  from  which  it  may  be  distinguished  by  not  being 
decolorized  by  a  solution  of  bichloride  of  mercury  (841). 
It  is,  however,  destroyed  by  boiling  nitric  acid,  chloride 
of  tin,  and  the  caustic  alkalies. 

864.  Solutions  of  acetate  of  lead,  chloride  of  barium, 
and  nitrate  of  silver,  produce  white  precipitates  of  me- 
conates,  which  are  all  soluble  in  an  excess  of  nitric  acid. 

*  Concentrated  sulphuric  acid,  to  which  0-004  per  cent,  of  nitric 
acid  (NO.)  has  been  added,  gives  a  violet  purple  color  when  gently 
heated  with  morphia  or  the  hydrochlorate  (Erdmann). 

f  If  possible  the  solution  should  be  set  aside  for  some  hours  in  or- 
der to  allow  the  morphia  to  crystallize  out. 


328  STRYCHNIA. 


CHAPTER  XIY. 

STRYCHNIA. 

865.  STRYCHNIA  (C^H^N^)  is  the  poisonous  alkaloid 
contained  in  nux  vomica  and  other  plants  of  the  strychnos 
tribe.  Although  a  very  minute  quantity  of  strychnia  is 
sufficient  to  cause  death,  the  symptoms  to  which  it  gives 
rise  are  usually  so  well  marked,  and  the  tests  by  which 
it  may  be  recognized  are  so  characteristic  and  delicate, 
that  less  difficulty  is  experienced  in  deciding  upon  the 
question  of  its  administration  than  in  the  case  of  most 
other  vegetable  poisons. 

Detection  of  Strychnia  in  Organic  Mixtures,  Tissues,  &c. 


>.  The  matter  under  examination,  which,  if  solid, 
should  be  cut  into  shreds  or  slices,  is  digested,  for  about 
an  hour,  in  a  dish  placed  upon  a  water-bath,  with  dilute 
hydrochloric  acid  (1  part  of  the  strong  acid  with  10  parts 
of  water).  The  solution  is  then  rendered  pretty  clear  by 
filtration  through  muslin,  or  paper,  evaporated  on  a  water- 
bath  to  as  small  a  bulk  as  convenient,  and  rendered 
strongly  alkaline  by  solution  of  potash.  The  alkaline 
solution  is  poured  into  a  narrow  stoppered  bottle,  and 
shaken  with  about  an  equal  volume  of  ether  for  several 
minutes ;  on  standing,  the  ether  will  rise  to  the  surface, 
holding  the  strychnine  in  solution.  The  ethereal  layer 
is  drawn  off  with  a  small  syphon  or  pipette,  and  evapo- 
rated to  dryness  in  a  small  capsule  placed  on  the  water- 
bath.  Very  minute  particles  of  the  solid  residue  may 
then  be  taken  on  the  point  of  a  knife,  and  examined  for 
strychnia  by  the  following  tests : — 

867.  The  extremely  bitter  taste  of  strychnia  is  per- 
ceptible even  when  a  very  minute  quantity  is  examined. 

868.  A  particle  of  the  suspected  substance  is  placed 


STRYCHNIA.  329 

upon  a  piece  of  white  porcelain,  and  beside  it,  but  not 
touching  it,  a  drop  of  strong  sulphuric  acid  is  placed 
with  a  glass  rod.  A  trace  of  solution  of  chromate  or 
bichromate  of  potash  is  introduced,  by  a  glass  rod,  into 
the  drop  of  sulphuric  acid,  and  the  particle  supposed  to 
contain  strychnia  is  then  pushed  into  it.  A  fine  violet 
blue  color  should  then  be  produced,  which  soon  changes 
into  red.* 

869.  Another  particle  of  the  substance  is   moistened 
with  strong  nitric  acid,  and  a  very  minute  quantity  of  the 
peroxide  (brown  oxide)  of  lead  is  added.     Violet  streaks 
should  arise   from  the    particles   of  the  peroxide,   and 
should  gradually  pervade  the  liquid,  ultimately  changing 
to  red. 

870.  If  the  results  obtained  by  these  tests  should  not 
be  satisfactory,  in  consequence  of  some  fatty  or  other 
organic  matter  having  also  been  dissolved  by  the  ether 
and  left  with  the  strychnine  on  evaporation,  the  remainder 
of  the  suspected  residue  (866)  in  the  capsule,  should  be 
moistened  with  strong  sulphuric  acid,  and  heated  for  some 
time  upon  the  water-bath,  when  the  extraneous  organic 
matters  will  be  carbonized,  and  the  strychnia  converted 
into  a  sulphate.     The  carbonaceous  mass  is  treated  with 
water,  filtered,  the  clear  solution   mixed  with  a  slight 
excess  of  ammonia,  and  shaken  with  about  one-sixth  of 
its  volume  of  chloroform  (for  which  ether  may,  in  case 
of  need,  be  substituted).!     When  the  chloroform,  hold- 
ing the  strychnia  in  solution,  has  fallen  to  the  bottom  of 
the  liquid,  the  latter  is  drawn  off  and  the  chloroform 
evaporated  upon  a  water-bath,  when  the  strychnia  will 
be  left  and  may  be  identified  by  the  tests  described  in 
868,  869. 

*  Although  the  presence  of  any  considerable  proportion  of  morphia 
interferes  with  the  detection  of  strychnia,  the  separation  of  the  two 
alkaloids  is  so  easily  effected  by  ether  or  benzole,  which  will  readily 
dissolve  strychnia,  but  scarcely  morphia,  that  there  is  no  danger  of 
strychnia  being  overlooked  from  this  cause. 

f  Benzole,  which  is  ligher  than  water,  and  less  volatile  as  well  as 
cheaper  than  chloroform  or  ether,  may  also  be  employed  for  the  ex- 
traction of  strychnia,  though  it  is  not  so  good  a  solvent  for  it  as  chlo- 
roform. 

28* 


330  NICOTIA. 


CHAPTER  XV. 

NICOTIA. 

871.  THE  poisonous  oily  alkaloid  of  tobacco,  nicotia, 
or  nicotine  (C10H7N),  has  occasionally  been  employed 
with  criminal  intention,  but  it  is  much  less  likely  to  be 
met  with  than  morphia  or  strychnia,  on  account  of  its 
very  powerful  and  characteristic  odor. 

Detection  of  Nicotia  in  Organic  Mixtures. 

872.  This  alkaloid  may  be  extracted  by  a  process 
similar  to  that  followed  in  the  case  of  strychnia  (866), 
viz.,  by  digesting  the  mixture  with  dilute  hydrochloric 
acid,  liberating  the  alkaloid  by  means  of  potash,  and 
removing  it  from  the  aqueous  solution  with  ether.     On 
allowing  a  few  drops  of  the  ethereal  solution  to  evapo- 
rate spontaneously,  impure  nicotia  will  be  left,  and  may 
be  recognized  by  its  pungent  odor  recalling  that  of  to- 
bacco.    In  order  to  obtain  the  nicotia  in  a  pure  state, 
the  ethereal  solution  must  be  shaken  with  water  mixed 
with  about  one-fifth  of  sulphuric  acid,  which  dissolves 
the  nicotia  in  the  form  of  sulphate.     The  ether  is  then 
poured  off,  and  the  aqueous  solution  of  sulphate  of  nico- 
tia is  shaken  with  a  little  more  ether  to  remove  any  fatty 
matters  which  may  be  present.     It  is  then  rendered  al- 
kaline by  potash,  and  again  shaken  with  ether,  the  ethe- 
real layer  containing  the  nicotia  being  afterwards  allowed 
to  evaporate  spontaneously,  when  oily  drops  of  nicotia 
are  left,  and  may  be  recognized  by  the  smell,  especially 
when  gently  heated.     If  ammonia  be  present,  it  may  be 
removed  by  exposing  the  nicotia  under  an  exhausted  re- 
ceiver containing  a  dish,  of  strong  sulphuric  acid. 


PHOSPHORUS.  331 


CHAPTER  XVI. 

DETECTION  OF  PHOSPHORUS  IN  CASES  OF  POISONING. 

873.  THE  comparative  frequency  of  accidental  poison- 
ing by  phosphorus  matches  in  the  hands  of  children,  to- 
gether with  the  circumstance  that  a  phosphorus  poison 
for  vermin  is  now  in  very  common  use,  render  it  neces- 
sary that  the  medical  chemist  should  be  able  to  obtain 
evidence  of  its  presence  in  organic  mixtures.    If  possible 
the  vomited  matter  should  be  especially  examined,  as 
they  have  been  found  to  contain  the  largest  proportion 
of  phosphorus. 

874.  If  the  substance  to  be  examined  has  not  been 
long  exposed  to  the  air,  it  may  still  contain  phosphorus 
in  the  free  state,  but  in  most  cases  oxidation  will  have 
converted  the  phosphorus  into  phosphorous  acid  (P03), 
or  possibly  even  into  phosphoric  acid  (P05).     Since  this 
last  is  a  normal  constituent  of  the  body  and  of  the  food, 
it  would  afford  no  evidence  of  the  administration  of 
phosphorus,  but  fortunately,  unless  after  prolonged  ex- 
posure, either  phosphorous  acid  or  phosphorus  itself  can 
be  detected  whenever  this  element  has  been  taken  into 
the  system. 

875.  The  organic  matter  should  first  be  examined  as 
to  its  odor,  that  of  phosphorus  being  very  characteristic, 
and  as  to  its  luminosity  in  the  dark.     It  should  also  be 
carefully  looked  over  to  ascertain  if  any  solid  particles 
of  the  phosphorized  composition  can  be  detected. 

876.  The  suspected  matter  is  then  placed  in  a  flask, 
and  acidulated  with  dilute  sulphuric  acid,  a  little  water 
being  also  added  if  necessary.     The  flask  is  connected 
by  means  of  a  cork  with  a  bent  glass  tube  passing  through 
a  wide  tube  (having  a  perforated  cork  at  each  end)  through 
which  a  stream  of  cold  water  can  be  kept  trickling.     On 


332  PHOSPHORUS. 

applying  a  moderate  heat  to  the  flask,  in  a  darkened 
room,  the  condensing  vapors  should  exhibit  a  phospho- 
rescent appearance.  The  liquid  which  distils  over  may 
possibly  contain  white  finely  divided  phosphorus.  If  it 
be  at  all  turbid  it  should  be  shaken,  in  a  tall  vessel,  with 
bisulphide  of  carbon,  which  will  dissolve  the  phosphorus 
and  sink  to  the  bottom.  On  allowing  the  bisulphide  of 
carbon  to  evaporate  spontaneously,  it  will  leave  the 
phosphorus,  often  in  a  spontaneously  inflammable  condi- 
tion. If  no  free  phosphorus  has  been  detected,  both  the 
distilled  liquid  and  that  remaining  in  the  flask  must  be 
examined  for  phosphorous  acid  by  the  following  process : 
877.  The  liquid  to  be  tested  having  been  acidulated 
with  sulphuric  acid,  is  placed  in  a  flask,  together  with  a 
few  fragments  of  pure  zinc.  A  cork  with  a  bent  tube  is 
then  attached  so  that  the  evolved  hydrogen  may  be  passed 
through  a  solution  of  nitrate  of  silver.  A  strip  of  filter- 
paper  moistened  with  nitrate  of  silver  may  also  be  sus- 
pended some  distance  above  the  surface  of  the  liquid  in 
the  flask.  Should  any  inconvenience  be  caused  by  the 
frothing,  a  little  alcohol  may  be  poured  upon  the  surface 
of  the  liquid.  If  any  phosphorous  acid  be  present,  phos- 
phuretted  hydrogen  (PH3)  will  be  evolved,  and  will 
produce  a  dark  precipitate  in  the  solution  of  nitrate  of 
silver,  and  a  mingled  gray  and  yellow  stain  upon  the 
filter  paper,  which  will  become  bright  yellow  when  dipped 
into  a  little  strong  nitric  acid.  (Sulphuretted  hydrogen 
would  merely  blacken  the  nitrate  of  silver,  and  the  stain 
would  be  dissolved  by  the  acid  without  turning  yellow.) 
The  dark  precipitate  (phosphide  of  silver,  Ag3P)  is  col- 
lected upon  a  small  filter,  washed,  dissolved  in  a  little 
hot  nitric  acid,  and  the  solution  evaporated  to  dryness. 
On  adding  a  little  water,  and  a  trace  of  ammonia  upon 
the  end  of  a  glass  rod,  the  yellow  precipitate  of  phosphate 
of  silver  (3AgO,P05)  will  be  produced.  The  character- 
istic odor  of  phosphuretted  hydrogen  should  also  be 
looked  for  in  this  experiment. 


DETECTION    OF    ALCOHOL.  383 


CHAPTER  XVII. 

DETECTION  OF  ALCOHOL  IN  ORGANIC  MIXTURES. 

878.  IN  cases  where  alcohol  (C4H602)  in  any  form  has 
been  taken  shortly  before  death,  it  may  generally  be  de- 
tected in  the  contents  of  the  stomach.     The  odor  having 
been  carefully  noticed,  the  organic  matter,  mixed  with  a 
little  water  if  necessary,  should,  if  acid,  be  exactly  neu- 
tralized with  potash,  and  distilled,  by  the  heat  of  a  water- 
bath,  in  a  flask  or  retort  connected  with  a  tube  carefully 
cooled  in  order  to  condense  the  vapors.  When  a  sufficient 
quantity  of  the  liquid  has  distilled  over,  it  may  be  exa- 
mined for  alcohol  by  the  following  tests : — 

879.  Observe  whether  it  has  the  smell  and  taste  of 
alcohol.     Dip  a  glass  rod  into  it  and  see  if  it  will  burn. 

880.  Mix  a  small  portion  with  dilute  sulphuric  or  hy- 
drochloric acid,  and  add  a  drop  of  solution  of  bichromate 
of  potash  (KO,2Cr03).     On  applying  heat  to  the  mixture, 
the  presence  of  alcohol  would  be  indicated  by  the  change 
of  the  orange  color  of  chromic  acid  (CrO3)  into  the  green 
of  oxide  of  chromium  (Cr?O3),  and  by  the  odor  of  aldehyde 
(C4H402)  at  the  mouth  of  the  tube. 

881.  The  remainder  of  the  alcoholic  distillate  may  be 
placed  in  a  tube,  and  dry  powdered  carbonate  of  potash 
added  to  it,  in  small  portions  as  long  as  it  is  dissolved. 
The  water  will  be  thus  taken  up  by  the  carbonate  of 
potash,  and  the  alcohol  will  rise  to  the  surface,  and  will 
now  be  found  to  be  inflammable,  although  it  may  have 
been  too  much  diluted  when  previously  tried. 


334  DETECTION    OF    POISONS 


CHAPTER  XVIII. 

GENEKAL   SYSTEMATIC    COURSE    FOR    THE    DETECTION    OF 
POISONS  IN  ORGANIC  MIXTURES. 

882.  ALTHOUGH  it   rarely  happens  that  an   organic 
mixture  is  submitted  to  examination  without  some  clue 
which  enables  the  chemist  to  limit  the  inquiry  to  a  very 
few  poisons,  still  such  a  case  should  be  provided  for,  and 
it  is  here  proposed  to  give  an  outline  of  a  systematic 
course  for  the  detection  of  the  leading  poisons,  in  three 
divisions,  referring  to  cases  where  (1)  the  poison  is  be- 
lieved to  be  metallic,  (2)  it  is  believed  to  be  an  organic 
poison,  and  (3)  nothing  whatever  is  known  about   it. 
Alcohol,  phosphorus,  opium,  and  hydrocyanic  acid  will 
not  be  included  in  this  course,  since  they  at  once  afford 
indications  of  their  presence,  and  may  be  detected  ac- 
cording to  the  directions  already  given. 

THE  POISON  IS  BELIEVED  TO  BE  METALLIC. 

Examination  for  Arsenic,  Antimony,  Mercury,  Copper,  Lead, 
Zinc,  Barium,  Silver,  Bismuth. 

883.  The  solid  portions  of  the  mixture  having  been 
as  finely  divided  as  possible,  with  a  sharp  knife  or  scis- 
sors, the  whole  is  heated  (for  about  an  hour)  in  a  porce- 
lain dish  placed  upon  a  water  bath,  with  a  mixture  of  six 
measures  of  water  and  one  of  hydrochloric  acid,*  to  which 
chlorate  of  potash  is  added  by  degrees,  with  constant 
stirring,  until  the  solid  has  disintegrated,  and  the  liquid 
is  sufficiently  thin  for  filtration.     It  is  then  filtered,  the 
insoluble  part  is  washed  several  times  with  water  (the 

*  If  there  be  much  liquid,  less  water  must  be  added  so  that  the 
acid  may  form  about  a  sixth  of  the  whole. 


IN    ORGANIC    MIXTURES.  335 

washings  being  mixed  with  the  filtrate),  and  is  then  set 
aside  for  further  examination  (892). 

884.  The  filtered  liquid  is  evaporated  on  a  water  bath, 
to  a  small  bulk,  and  subjected  to  electrolysis  as  directed 
in  753.     After  the  passage  of  the  current  has  been  con- 
tinued for  about  an  hour  (during  which  the  exit  tube  has 
been  heated  in  order  to  detect  arsenic  and  antimony  (753, 
766),  about  half  a  drachm  of  a  strong  solution  of  washed 
sulphurous  acid  is  poured  down  the  funnel  tube;  the  exit 
tube  having  been  first  changed  if  any  deposit  should 
have  been  formed  in  it. 

885.  After  the  current  has  passed  for  another  half 
hour,  the  electro-negative  platinum   plate  is   removed 
from  the  decomposing  cell,  without  suspending  the  cur- 
rent, and  washed  with  a  little  distilled  water.    The  liquid 
in  the  cell  is  reserved  for  subsequent  examination  (888). 

886.  The  appearance  of  the  deposit  upon  the  electro- 
negative plate  having  been  carefully  observed,  it  is  boiled 
with  a  little  dilute  yellow  hydrosulphate  of  ammonia, 
which  will  dissolve  the  antimony,  to  be  detected  in  the 
solution  according  to  763  (e). 

887.  The  plate  is  again  well  washed,  and  boiled  witfP 
dilute  nitric  acid.     The  solution  is  boiled  down  (in  a 
test-tube)  to  a  very  small  bulk,  and  mixed  with  an  ex- 
cess of  ammonia.     The  presence  of  copper  will  be  indi- 
cated by  the  blue  color.    Hydrochloric  acid  is  very  care- 
fully added  till  the  solution  is  slightly  acid,  and  it  is  then 
largely  diluted  with  water.     A  milkiness  will  be  pro- 
duced if  bismuth  be  present.     The  liquid  is  again  evapo- 
rated to  a  small  bulk,  rendered  clear  by  adding  a  little 
hydrochloric  acid,  and  boiled  with  a   strip  of  bright 
copper,   to   detect   mercury    (770,  771).      In    case  any 
mercury  should  have  been  left  upon  the  platinum  in  the 
form  of  sulphide,  the  plate  may  be  again  boiled  with 
dilute  nitric  acid  and  a  drop  of  hydrochloric  acid  (taking 
care  not  to  dissolve  much  of  the'platinum).    The  solution 
is  boiled  down  to  a  small  bulk,  mixed  with  excess  of 
ammonia,  then   with  hydrochloric  acid  in  excess,  and 
boiled  with  copper. 

888.  The  liquid  which  has  been  subjected  to  electro- 
lysis (885)  is  now  evaporated  at  a  moderate  heat,  until 


336  DETECTION    OF    POISONS 

the  organic  matter  is  so  far  carbonized  that  a  small  por- 
tion, when  diluted  with  water,  and  filtered,  yields  a 
nearly  colorless  solution.  The  whole  is  then  mixed 
with  a  few  drops  of  hydrochloric  and  nitric  acids,  heated 
to  boiling,  again  diluted  and  filtered.  The  carbonaceous 
residue  is  washed  and  reserved  for  further  examination 
(891). 

889.  The  filtrate  and  washings  are  saturated  with  sul- 
phuretted hydrogen,  boiled,  again  saturated  with  sulphu- 
retted hydrogen  and  set  aside  in  a  warm  place,  in  a 
covered  vessel,  for  several  hours.     Any  precipitate,  ex- 
cept sulphur,  which  may  have  been  deposited,  is  filtered 
off,  washed,  and  examined  for  metals  according  to  the. 
general  method  followed  in  qualitative  analysis. 

890.  The    solution    filtered    from  this   precipitate   is 
evaporated  to  a  small  bulk,  and  mixed  with  an  excess  of 
ammonia.    If  this  should  produce  a  precipitate  (generally 
consisting  of  earthy  phosphates  or  peroxide  of  iron),  it  is 
filtered  off,  and  the  solution  mixed  with  a  little  hydro- 
sulphate  of  ammonia  to  precipitate  any  zinc  as  sulphide, 
which  may  be  tested  by  the  blowpipe  (803c):* 

*  891.  The  carbonaceous  residue  from  888  is  dried,f 
incinerated,  and  examined  together  with  the  other  incine- 
rated residue  from  883. 

892.  The   residue   left   undissolved   by    hydrochloric 
acid  and  chlorate  of  potash  in  883  is  dried  and  incinerated 
at  a  low  red  heat.     The  ash-  is  mixed  with  that  obtained 
in  891,  and  boiled   with  nitric  acid  diluted  with  two 
volumes  of  water.     The  solution  is  filtered  and  examined 
for  metals  as  usual  in  qualitative  analysis. 

893.  Any  portion  of  ash  left  undissolved  by  the  nitric 
acid  is  washed,  dried,  and,  if  still  retaining  any  carbon, 
again  incinerated.     The  residue,  which  might  possibly 
contain  barium  (as  sulphate),  silver  (as  chloride),  and 

*  If  tliis  precipitate  is  very  dark  and  impure,  it  must  be  dissolved 
in  a  mixture  of  hydrochloric  and  nitric  acids,  the  solution  evaporated 
to  dryness,  the  residue  heated  till  all  organic  matter  is  destroyed,  and 
dissolved  in  nitric  acid.  The  solution  is  mixed  with  excess  of  am- 
monia, filtered,  if  necessary,  and  tested  with  hydrosulphate  of  am- 
monia. 

f  A  small  charcoal  fire  will  be  found  very  convenient  in  these 
incinerations. 


IN    ORGANIC    MIXTURES.  337 

lead  (as  sulphate),  is  fused  with  three  or  four  parts  of 
carbonate  of  soda  in  a  porcelain  crucible.  The  fused 
mass  having  been  boiled  with  water,  the  residue  is  washed 
till  the  washings  leave  nothing  on  evaporation,  and  dis- 
solved in  hot  dilute  nitric  acid.  The  nitric  solution  is 
tested  (1)  for  silver  with  hydrochloric  acid,  which  would 
give  a  white  precipitate,  soluble  in  ammonia  (2)  for 
barium  with  sulphate  of  lime  (white  precipitate*)  and 
hydrofluosilicic  acid  (white  crystalline  precipitate),  (3) 
for  lead  with  dilute  sulphuric  acid  (white  granular  preci- 
pitate), and  hydrosulphuric  acid  (purplish  black  precipi- 
tate). 

THE   POISON  IS  BELIEVED  TO   BE  ORGANIC. 

Examination  for   Oxalic  Acid,  Morphia,   Strychnia,  Nicotia 
and  Conia. 

893a.  The  organic  mixture,  of  which  the  solid  portions 
have  been  as  finely  divided  as  possible,  is  digested  in 
water  acidulated  with  hydrochloric  acid,  for  an  hour 
or  two,  in  a  dish  placed  upon  a  wash-bath.  The  solution 
is  then  filtered,  first  through  muslin,  and  afterwards 
through  paper,  and  evaporated  upon  the  water-bath  to 
a  small  bulk. 

894.  A  small  portion  of  this  solution  is  tested  for 
oxalic  acid  by  adding  a  little  chloride  of  calcium,  then 
ammonia  in  excess,  and  finally,  acetic  acid  in  excess.     If 
any  white  crystalline  precipitate  of  oxalate  of  lime  be  left 
undissolved  by  the  acetic  acid,  the  larger  portion  of  the 
solution  must  be  examined  for  oxalic  acid  according  to 
Chapter  XI. 

895.  The  remainder  of  the  solution  from  893a  is  ren- 
dered pretty  strongly  alkaline  by  potash,  and  shaken 
with  four  or  five  times   its   volume  of  ether,  f     After 

*  If  this  precipitate  be  collected  on  a  filter,  well  washed,  and  heated 
on  a  platinum  wire  moistened  with  hydrochloric  acid,  in  the  inner 
blowpipe  flame,  it  will  tinge  the  outer  flame  bright  green. 

t  Uslar  and  Erdmann  have  recommended  amylic  alcohol  as  a  sol- 
vent for  the  poisonous  alkaloids,  but  the  advantage  with  which  its 
employment  in  certain  cases  may  be  attended  is  in  great  measure  coun- 
terbalanced by  the  very  disagreeable  and  injurious  character  of  its 
vapor. 

29 


338  DETECTION    OF    POISONS,    ETC. 

standing  for  some  time,  the  ethereal  layer  is  poured  off 
or  drawn  off  with  a  small  syphon  or  pipette. 

896.  The  ethereal  solution  is  poured  into  a  dish  and 
allowed  to  evaporate  spontaneously.     If  either  nicotia 
or  conia  be  present,  it  will  be  left  in  oily  drops  which 
will  evolve  the  powerful  odor  of  the  base  when  gently 
heated  on  the  water-bath.     If  any  solid  residue  be  left 
by  the  ether,  it  must  be  examined  for  strychnia  and  mor- 
phia.    For  this  purpose  it  is  dissolved  in  a  very  little 
dilute  hydrochloric  acid,  filtered,  if  necessary,  and  the 
solution  rendered  alkaline  with  carbonate  of  soda,  briskly 
stirred,  and  set  aside  for  an  hour  or  two.     If  any  crys- 
talline precipitate  is  formed,  it  must  be  examined  for 
strychnia  and  morphia  according  to  868,  869,  859.     The 
solution  in  which  carbonate  of  soda  has  failed  to  produce 
a  precipitate,  or  which  has  been  filtered  from  the  preci- 
pitate, is  evaporated  to  dryness  on  a  water-bath,  and  the 
residue  gently  heated  with  absolute  alcohol.     The  alco- 
holic solution  is  evaporated  to  dryness,  and  the  residue 
tested  for  strychnia  and  morphia. 

897.  The  aqueous  layer  separated  in  895  is  slightly 
acidified  with  hydrochloric  acid,  and  evaporated  to  dry- 
ness  on  the   water-bath.     The  residue  is  heated    with 
strong  alcohol  for  some  time.     The  alcoholic  solution  is 
filtered  and  evaporated  to  dryness  on  the  water-bath. 
The  residue  is  redissolved  in  a  very  little  water,  the  so- 
lution briskly  stirred  with  a  slight  excess  of  carbonate 
of  soda,*  and  the  further  examination  conducted  pre- 
cisely as  in  896. 

NOTHING  IS  KNOWN  OF  THE  NATURE  OF  THE  POISON. 

898.  In  this  case,  the  first  part  of  the  process  must  be 
conducted  on  the  supposition  that  the  poison  is  organic 
(893a) ;  the  residues  left  undissolved  by  alcohol  in  896, 
897,  as  well  as  so  much  of  the  precipitate  produced  by 
carbonate  of  soda  as  is  not  consumed  in  testing  for  alka- 

*  If  oxalic  acid  be  present,  it  might  go  down  in  this  precipitate  as 
oxalate  of  lime.  The  remainder  of  the  oxalic  acid  will  be  found  as 
oxalate  of  soda  in  the  residue  left  by  absolute  alcohol  in  extracting 
the  morphia. 


SEPARATION    OF    POISONS    BY    DIALYSIS.      839 

loids,  must  be  dissolved  in  hydrochloric  acid,  mixed  with 
the  original  organic  matter  left  undissolved  by  the  hydro- 
chloric acid  (893a),  and  the  examination  for  metallic 
poisons  proceeded  with  as  in  883. 


CHAPTER  XIX. 

SEPARATION  OF  POISONS  FROM  ORGANIC  MIXTURES 
BY  DIALYSIS. 

899.  THE  important  observation  made  by  Mr.  Graham 
that  crystallizable  bodies  will  pass  in  a  state  of  solution 
through  membranous  and  other  diaphragms  which  will 
not  permit  the  passage  of  the   amorphous   substances 
composing  the  bulk  of  most  organic  mixtures,  has  been 
applied  by  him  to  the  separation  of  poisons.     As  the 
process  is  very  simple,  easy  of  execution,  and  does  not 
involve  any  operations  which  would  interfere  with  the 
subsequent  application  to  the  same  mixture 

of  any  other  process  for  the  separation  of  the 
poison,  it  will  probably  come  into  very  general 
use  in  medico-legal  investigations. 

This  process  is,  indeed,  a  refined  filtration, 
and  is  applicable  instead  of  that  operation,  in 
all  the  steps  of  the  separation  of  poisons 
from  organic  mixtures,  with  this  very  great 
advantage,  that  it  removes  not  only  substances 
mechanically  suspended  in  the  liquid,  as  is 
the  case  with  filtration,  but  also  coloring  matters,  albu- 
minous substances,  &c.,  which  so  interfere  with  the  ap- 
plication of  tests  to  the  liquid  obtained  by  filtration. 

900.  A  circular  piece  of  parchment-paper^ (see  note 
to  p.  284)  is  folded,  as  in  preparing  a  filter,  into  a  cone, 
which  should  be  at  least  twice  as  large  as  is  necessary  to 
contain  the  mixture  under  examination.     This  cone  is 
placed  in  the  mouth  of  a  cylindrical  jar  (Fig.  82),  (a  bea- 

*  This  should  have  been  well  soaked  in  distilled  water,  and  dried 
before  use. 


340      SEPARATION    OF    POISONS    BY    DIALYSIS. 

ker  or  common  tumbler),  filled  nearly  to  the  brim  with 
water,  the  volume  of  which  should  be  about  eight  times 
that  of  the  organic  mixture. 

901.  The  solid  portion  of  the  organic  matter  having 
been  cut  up,  and,  if  it  be  thought  necessary,  a  little  water 
having  been  added  to  thin  the  mixture,  it  may  be  poured 
at  once  upon  the  cone  of  parchment-paper  arranged  as 
above  directed.     The  whole  may  then  be  covered  with  a 
bell-glass,  or  placed  in  a  secure  cupboard,  and  left  for  as 
long  a  period  as  can  be  conveniently  allowed  to  elapse, 
if  possible,  for  at  least  forty-eight  hours.     The  diffusate, 
as  the  liquid  in  the  glass  is  termed,  may  then  be  evapo- 
rated to  a  small  bulk  and  examined  for  the  poison  by 
the  appropriate  methods,  whilst  the  organic  mixture  re- 
maining upon  the  cone  or  dialyser  may  be  subjected  to 
the  ordinary  processes  for  the  separation  of  poison  from 
organic  matter. 

902.  Of  course,  in  cases  where  there  is  reason  to  sus- 
pect the  presence  of  hydrocyanic  acid,  alcohol,  or  phos- 
phorus, it  would  not  be  prudent  to  subject  the  mixture 
to  dialysis  until  at  least  a  portion  of  it  had  been  examined 
for  those  poisons. 

903.  If  time  could  be  spared,  it  would  evidently  be 
desirable  to  dialyse  the  organic  mixture  at  first  without 
any  addition  (except  water),  since   not  only  would  all 
questions  of  impurity  in  the  reagents  be  avoided,  but  a 
knowledge  of  the  state  of  the  poison,  whether  soluble  or 
not,  would  be  thus  gained,  which  might,  in  many  cases, 
prove  of  great  service.     The  mixture  might   then  be 
dialysed  a  second  time  after  digestion  with  the  proper 
solvent,  such  as  hydrochloric  acid,  or  that  acid  with  the 
addition  of  chlorate  of  potash.* 

*  The  Editor  has  obtained  most  satisfactory  results  by  this  process 
in  separating arsenious  acid,  strychnine,  morphine,  opium,  and  oxalic 
acid  (as  oxalate  of  lime).  The  arsenious  acid  was  separated  in  some 
cases  by  simply  dialysing  the  organic  mixture,  in  others  by  digesting 
with  hydrochloric  acid  and  dialysing,  and  in  others  by  first  digesting 
with  hydrochloric  acid  and  chlorate  of  potash.  In  all  cases  the  dif- 
fusate was  colorless. 


APPENDIX. 


WEIGHTS  AND  MEASURES. 

Troy  or  Apothecaries1  Weiyht. 


Pound.      Ounces.     Drachms.     Scruples. 
1     =     12    = 
1     = 


Grains.      French  Grammes. 


Pound. 
1 


Gallon. 
1 


Ounces. 

16 

1 


Pints. 
8 
1 


96     =     288 

=     5760 

— 

372-96 

8     =       24 

=      480 

—  - 

31-08 

1     =        3 

=        60 

__ 

3-885 

1 

=        20 

— 

1-295 

1 

= 

0-0647 

Avoirdupois 

Weiyht. 

Drachms. 

Grains. 

French  Grammes. 

=        256        = 

7000 

—. 

453-25 

=          16        = 

437-5 

.  — 

28-328 

1        = 

27-040 

S5 

1-77 

Imperial  Measure. 

Fluidounces. 

Fluidrachms. 

Minims. 

1GO          = 

1280 

S= 

76800 

20        = 

160 



9600 

1        = 

8 

= 

480 

1 

= 

60 

Weight  of  Water  at  62°,  contained  in  the  Imperial  Gallon, 

Grains. 

1  Imperial  gallon       .         .         .     =     .         .     70000 
1         "         pint  .         .         .     =     .         .       8750 


fluidounce 
fluidraclmi 
minim 


437-5 
54-7 
0-91 


Cubic  Inches  contained  in  the  Imperial  Gallon,  frc. 

Cubic  Inches. 

1  Imperial  gallon        .         .  .  =  .  .  277-276 

1         "         pint           .         .  .  =  .  .  34-659 

1         "         fluidounce          .  .  =  .  .  1-732 

1         "         fluidrachm        .  .  =  .  .  0-2166 

1         "         minim       .         .  .  =  .  .  0-0036 
29* 


APPENDIX. 


FRENCH  WEIGHTS  AND  MEASURES. 

Measures  of  Length. 


Millimetre 
Centimetre 

English  Inches. 

=              -03937 
=              -39371 

Decimetre 

— 

3 

•93710 

Metre 

—  . 

39 

•37100 

Mil. 

Fur. 

Yds. 

Feet. 

In 

Decametre 

— 

393 

•71000 

=  0 

0 

10 

2 

9- 

7 

Hecatometre 

— 

3937 

•10000 

=  0 

0 

109 

1 

1 

Kilometre 

=r= 

39371 

•00000 

=  0 

4 

213 

1 

10- 

2 

Myriometre    =  393710.00000  =  6      1      156      0 
Measures  of  Capacity. 


Cubic  Inches. 


English  Imperial  Measure. 
Gal.  Pints.  F.oz.  F.drms.   Min. 


Cubic  Centimetre  ) 
or  Millilitre        ) 

•06102 

= 

0 

0 

0 

0 

16-3 

Centilitre        = 

•61028 

ig- 

0 

0 

0 

2 

43 

Decilitre         = 

6 

•10280 

—  — 

0 

0 

3 

3 

2 

Litre               = 

61 

•02800 

— 

o 

1 

15 

1 

43 

Decalitre        = 

610 

•28000 

• 

2 

1 

12 

1 

16 

Hecatolitre     = 

6102 

•80000 



22 

0 

1 

4 

40 

Kilolitre          = 

61028 

•00000 

=    220 

0 

12 

6 

24 

Myriolitre      =  610280-00000 

=  2200 

7 

13 

4 

48 

J&usures  of  \Vripht. 

En 

gush  (.rams. 

Milligramme 

— 

•0154 

Centigramme 

= 

•1543 

Decigramme 

= 

1 

•5432 

Avoirdupois. 

Gramme 

— 

15 

•4323 

Ponn.  Gun. 

Drm. 

Decagramme 

= 

154 

•3234 

== 

0 

0 

5- 

65 

Hecatogramme 

== 

1543 

•2348 

= 

0 

3 

8- 

5 

Kilogramme 

==       15432-348       == 

2 

3 

5 

Myriogramme 

= 

154323 

•480 

= 

22 

1 

2 

INDEX. 


ACID,  arsenious  .......        275 

detection  of,  in  organic  mixtures,  Ac.  .  .  36 

benzoic  .......  35 

butic        , 228 

butinic     ........         228 

butyric    .......  228,  245 

caprylic  .... 

carbonic,  estimation  of .  .  .  .  .  .         260 

cholalic    ........         240 

choleic     ........         240 

cholic       ........         239 

choloidic  .......         240 

excretolio  .....  .         167 

formic      ........  26 

glycocholic          .......         239 

hippuric  :......  33 

hydrochloric,  detection  of,  in  organic  mixtures,  Ac.     .  .         313 

quantitative  determination  .  .  .         314 

hydrocyanic,  detection  of,  ip  organic  mixtures,  Ac.     .  .         320 

quantitative  determination  .  .  .         324 

inosic       ........         244 

lactic        .......  227,  244 

lithic        ........  31 

meconic  ........         325 

myristic  ........         228 

nitric,  detection  of,  in  organic  mixtures,  Ac.    .  .  .         315 

oxalic      ......  .317 

quantitative  determination          .  .  .  .319 

phosphoric,  detection  of  .  .         43,  44,  46 

quantitative  determination  .  .    55,  58 

prussic     .  ......         32  u 

sarcolactic  .......         244 

sulphuric,  detection  of,  in  organic  mixtures,  Ac.  .         311 

quantitative  determination  ....  56 

in  urine  .  60 

taurocholic          .....  .         289 

uric          ........! 

in  the  blood  ......         219 

xanthoproteic      ....  ISO 

Adulterations  of  milk  .......         236 

Albumen  .  .  .  .  .  .  .  .          IsO 

in  urine,  estimation  of  .....         146 

tests  for  .  .  .  .  .  .  .80 

Albuminose        .  .  .  .  .  .  .  .1^1 

Albuminous  urine  7'J 


344 


INDEX. 


Alcohol,  detection  of,  in  organic  mixtures 
Alkaline  phosphates,  determination  in  urine  . 

salts  of  the  urine 

Alkapton  in  urine  .... 

Ammonia,  detection  of,  in  organic  mixtures    . 

determination,  in  urine 
Ammoniacal  salts  of  the  urine 
Amyloid,  animal  .... 

Animal  charcoal,  purification  of 
Animalcules  in  the  blood    ' 
Anaemia,  blood  in  .... 

Annatto  in  milk  .... 

Antimony,  detection  of,  in  organic  mixtures  . 

the  tissues 
determination  of 
electrolytic  test  for  . 
galvanic  test  for 
Reinsch's  test  for     . 

Apothecaries'  weight     .... 
Arsenic,  detection  of,  in  copper 

hydrochloric  acid 
organic  mixtures 
oily  or  fatty  matters 
paper-hangings 
the  tissues     . 
determination  of 
electrolytic  test  fof 
Marsh's  test  for 
reduction  test  for 
Reinsch's  test  for 
Arsenic  acid,  separation  of 
Arsenious  acid 
Ass,  milk  of 
Avoirdupois  weight 

BARIUM,  detection  of,  in  organic  mixtures 
Becquerel,  his  analysis  of  urine 

and  Vernois,  their  analysis  of  milk 
and  Rodier,  their  analysis  of  blood 
Benzonitrile       . 
Berzelius,  his  analysis  of  bone 
urine 
Bile,  composition  of 

tests  for     . 
Biliary  calculi  .  ... 

matter  in  the  blood 
urine 

Biliphaeine  • 

Biliverdine         .  . 

Bismuth,  detection  of,  in  organic  mixtures     . 
Blood     ...... 

analysis  of 

containing  animalcules  . 
biliary  matter 
excess  of  albumen 

cholesterin  . 
corpuscles  . 
fat  . 
fibrin 


INDEX.  345 


Blood,  containing  excess  of  saline  matter         .  .  .219 

urea  .....         217 

uric  acid     .....         219 

water          .  .  .  .  .211 

pus      .......         222 

sugar  .  ....        220 

corpuscles  .  ....        171 

crystals    ........         179 

detected  in  organic  mixtures      .  ...         207 

on  clothing        ......         175 

in  milk     .  ......        235 

in  urine  .  ... 

quantitative  analysis  of  .  .  .  .190 

stains  of,  identified          ...  175 

Bone       .....  .  .254 

diseased     ...  .262 

quantitative  analysis  of   . 

Bottger's  test  for  sugar  •  •  76 

Bright's  disease,  urine  in          ...... 

BrUcke's  process  for  extracting  sugar  .  .78 

test  for  bile     .  .... 

Burette  .  ......          98 

CALCULI,  biliary  .......         163 

cystic  .......         158 

fusible  .......         156 

hempseed        .  .  .  .         157 

incombustible  ......         161 

mulberry        .  ....         156 

oxalate  of  lime  .  .  .  .  .  .156 

phosphatic      .  •  .         153 

qualitative  examination  of   .  .  .  .159 

triple  phosphate         ....  .         154 

urate  of  ammonia      ......         153 

uric  acid         ...  .  .151 

urinary  .  .  .  .  .  .  .150 

Calomel,  detection  of,  in  organic  mixtures,  &c.  .  .         295 

Carbonic  acid,  estimation  of  .  .         260 

Cartilage  ........         254 

Casein    ....  .         225 

Casts,  fibrinous  ....  ...  82 

Chalkstones        .  .164 

Charcoal,  animal,  purification  of  ...  29 

Chlorine,  determination  of,  in  urine     .  .     55,  60 

Chlorosis,  blood  in         .....  .         212 

Cholepyrrhin      ........         222 

Cholera,  blood  in  .......         212 

Cholesterin         .  .  .  .  .  .  .  .163 

in  the  blood  ......         216 

Choline  .........         239 

Chondrin  ....  266 

Chylous  urine    ........  87 

Collin     .........         266 

Colostrum          ........         228 

Combustible  calculi,  examination  of  .  .  .  .  160,  162 

Concretions,  gouty        .......         164 

Conia,  detection  of,  in  organic  mixtures,  Ac.  .  .  .         338 

Copper,  detection  of,  in  organic  mixtures,  Ac.  .  .  .         304 


346  INDEX. 

FADE 

Copper,  electrolytic  test  for       ...  .  306 

examination  of,  for  arsenic     .....         280 

quantitative  determination  of  .  .  .  .         306 

standard  alkaline  solution  of  .  .  .  .142 

Corpuscles  in  blood       .......         212 

Corrosive  sublimate,  detection  of,  in  organic  mixtures,  <fec.   .  .         294 

Cow,  milk  of      ........         281 

Creatine  (kreatine)        .......         242 

Creatinine  (kreatinine)  ......         243 

Cystine  calculi  .  .  .  .  .  .  .158 

tests  for  .....  .121 

DEPOSITS,  urinary,  examination  of     .  .         124 

microscopic  examination  of  .  .  .131 

Diabetes,  blood  in  .  .         220 

Diabetic  urine  .             .             .             .  .  .          •  .  .71 

quantitative  analysis  of  .  .  .  .137 

Dialysis,  separation  of  poisons  by  .  .  .  .         339 

Dumas,  his  analysis  of  blood     .             .  .  .  .  .         209 

EARTHY  phosphates,  determination  of,  in  urine  .  .  .53,  59 

salts  of  the  urine  ......  44 

Electrolytic  test  for  antimony  ......         293 

arsenic        .  .  .  .  .  .         276 

bismuth      ......         335 

copper         ...... 

mercury     ......         252 

Epithelium          ........  38 

Ewe,  milk  of     .  .  .  .  .  .  .  .231 

Excrements,  solid  .  .  .  •  .  .         167 

Excretine  .  .  ...  .  .  .  .168 

Extractive  matters  of  the  blood  .....         185 

urine  ... 

FAT,  detected  in  organic  mixtures        ... 

globules  in  milk    .......  227 

Fatty  acids,  earthy  salts  of,  in  urine    .  .  .126 

volatile,  in  serum  ...                           .  186 

matters  of  the  blood       ......  186 

in  excess  in  the  blood    .....  215 

Feces,  constituents  of    .             .             ...             .             .             .  167 

Fermentation  test  for  sugar       ......  76 

Fibrin    ....                          ....  181 

excess  or  deficiency  of,  in  blood              ....  214 

in  urine  .  .  .  .  .  . '  .  .82 

soluble     ........  182 

Fibrinous  casts  ........  82 

Figuier's  process  for  analysis  of  blood              ....  221 

Flesh,  juice  of  .                           ......  242 

Frothing,  prevention  of  ..... 

Fusible  calculi  ........  155 

GALACTINE        ........        231 

Gall-stones 163 

Gelatine  ........         254 

Globules,  organic  .......  86 

Glutin     .  .  .  .  .  .  .  .255 

Glycocine  .  .  .  -  ,  .  •  .  36,  240 


INDEX.  ;;i7 

PAOK 

Olycogeno           .             .             .  .             .             .             .             .241 

(nun  in  milk,  detection  of  .             .             .             .             .237 

<!onl,  milk  of     ...  231 

Gouty  concretions          .  ....         164 


........  178 

Haemato-cr3rstalline       .......  179 

ll:tMii:itnidin        ........  179 

Heller's  test  for  bile      .......  84 

Hempseed  calculi  .....  .157 

Jlrj'.-itinc                ........  291 

Hippuric  acid     ........  :>:{ 

excess  of,  in  urine            .....  67 

Hydrochloric  acid,  detection  of,  in  organic  mixtures               .              .  313 

quantitative  determination  «f                      .             .  314 

Hydrocyanic  aeid,  detection  of,  in  organic  mixtures,  <fcc.        .             .  320 

Henry  and  Humbert's  test  for         .  .  .322 

Liebig's  test  for                    .             .             .             .  321 

quantitative  determination  of                     .             .  324 

Sch«ele's  test  for     .             .             .             .              .  321 

sulphur  test  for                     .             .             .             .  322 

Hypoxanthine    .                          ......  244 

IMPERIAL  measure         .......  341 

Incineration  of  organic  matter              .....  52 

Indigo  extracted  from  urine      .....  .40 

Inosite    .........  244 

detection  of,  in  organic  mixtures            ....  '208 

Iodide  of  potassium,  detection  of,  in  organic  mixtures                          .  310 

Iodine,  detection  of,  in  organic  mixtures         ....  309 

in  the  urine          .-  H2 

JDICE  of  flesh    ..........         242 

KIKSTEIN  ......  .  .87 

Kreatine  ........         242 

detection  of,  in  organic  mixtures        ....         268 

Kreatinine  .  .  .  .  .  .  .  .243 

determination  of,  in  urine  ..  37 

LACTIC  acid       .......  227,  2-14 

Lactine  .........         220 

Lactometer         ........         238 

Lead  detected  in  water  ......         299 

detected  in  the  tissues      ......         :-!()3 

search  for,  in  organic  mixtures    .  .  .  .  ."<'() 

Lecithine  ........         239 

Leucine  ........         273 

Liebig's  process  for  estimating  urea      .  .  .  .  % 

Liquor  sanguinis  .  .  .  .  .  .  .171 

Liver,  saccharine  matter  from  .  .  ...  .  .         241 

Lithate  of  ammonia       .  .  .  .  .  .  .32,  65 

lithia  .......  33 

potash  .......  32 

soda  .  .  .  .  .  .       •       . 

Lithic  acid         .  .  .  .  .  .  .  .31 

detected  in  organic  mixtures          .  .  .  .271 

excess  of  in.  urine    .  64 


348  INDEX. 

PAGE 

MARGARINE       ........        228 

Marsh's  test  for  arsenic  ....  .         277 

Maumene's  test  for  sugar          .  .  .  .  .  .75 

Meconic  acid      ........         325 

Mercury,  detection  of,  in  organic  mixtures      ....         295 

electrolytic  test  for  .  .  .  .  .         297 

galvanic  test  for  .  .  .  .  .297 

Lassaigne's  test  for  ...         296 

nitrate,  preparation  of  97 

Microscopic  examination  of  urinary  deposits  .  .         131 

Milk ...         224 

adulteration  of  .  .  .  .  .         236 

containing  blood     .......         235 

pus  .         235 

detected  in  organic  mixtures         .  .  .        269 

globules      ........         227 

human,  composition  of  .  229 

morbid        .....  .  234 

quantitative  analysis  of      ...  .  232 

sugar  of  .  .  .  .  .226 

valuation  of  .......         237 

Milky  blood        ...  .  .216 

Millon's  test  for  albumen          .....  81 

Mixed  animal  fluids,  examination  of    .  .  .  .  .         272 

Moore's  test  for  sugar    .....  .75 

Morbid  blood    .........         210 

bone       ........         262 

milk       .  .....        234 

mucus    .  .  .  .  .  .  .  .        248 

urine      .  .  .  .  . '  .  .  .63 

Morbid  urine,  qualitative  examination  of  .  .  .94 

Morphia,  detection  of  .  .  .  .  .  .  .        326 

Mucus    .........         245 

morbid    .....  248 

quantitative  analysis  of ...  .  247 

NICOTIA,  detection  of,  in  organic  mixtures     ....  330 

Nitrate  of  urea  .....  30 

Nitric  acid  detection  of,  in  organic  mixtures  ....  315 

in  stains  on  clothing                           .             .  317 

Nux  vomica       ...                          .                                       .  328 

OLEINE               ...  .228 

Opium,  detection  of,  in  organic  mixtures          .  .         325 

Organic  globules  in  urine          .                                    j,  86 

Osseine  ......  .         254 

Oxalate  of  lime  calculi              ....  .         156 

deposits 

of  urea ......  .29 

Oxalic  acid,  detection  of,  in  organic  mixtures  .         317 

quantitative  determination  of       .  .         319 

PALMITJNE         ........  228 

Paper-hangings,  detection  of  arsenic  in           ....  290 

Parchment  paper             .             .             .             .            .  •             •             .  284 

Peptone               ........  181 

Pettenkofer's  test  for  bile          .  83 

Phospkato  of  ammonia  and  magnesia  calculi  154 


INDEX. 


349 


Phosphate  of  lime  calculi 

crystals,  in  urine     . 
Phosphates,  determination  of,  in  urine 
Phosphoric  acid,  general  process  for  determining 
Phosphorous  acid,  detection  of,  in  organic  mixtures 
Phosphorus         ..... 

Pipette   ...... 

Poisons,  detection  of,  in  organic  mixtures,  <fcc. 

separation  of,  by  dialysis 
Protein  ...... 

Prussic  acid,  detection  of,  in  organic  mixtures 
quantitative  determination  of  . 
Scheele's  test  for  . 

Sulphur  test  for  ... 

Purpurine          ..... 

Pus         ...... 

blue  ...... 

in  blood      ..... 

in  milk        ..... 

in  urine       .  ... 

quantitative  analysis  of 

Pyin 

Pyocyanine        ..... 

REDUCTION  test  for  arsenic 
Reinsch's  test  for  antimony 
arsenic 

SARCINE  .  ... 

Sarcolactic  acid  .... 

Sarcosine  ..... 

Scheele's  green  .  .  . 

Semen     .  ... 

Serolin  .  ... 

Serum,  composition  of  ... 

Silver,  detection  of,  in  organic  mixtures 
Specific  gravity  of  urine  taken 
Spermatozoa  .... 

Stains  of  blood  identified 
Starch-granules  .... 

Stearin  e  ..... 

Strychnia,  detection  of,  in  organic  mixtures    . 

identification  of 
Sugar,  Bbttger's  test  for  ... 

detected  in  organic  mixtures    . 

diabetic  ..... 

fermentation  test  for 

in  blood  .... 

in  healthy  urine 

in  urine,  estimation  of  . 

Maumene's  test  for 

Moore's  test  for  ... 

of  flesh  (inosite) 

of  liver 

of  milk    ..... 
determination  of 

tests  for  .... 

Trommer's  test  for 

30 


350        -  INDEX. 


Sugar,  volumetric  determination  of     .             .             .             .             .  142 

Sulphate  of  indigo,  detection  of,  in  organic  mixtures              .             .  312 

Sulphuric  acid,  detection  of,  in  organic  mixtures        .             .             .  •  311 

in  stains  on  clothing      .            .            .  312 

Syntonin             ........  184 

System  for  analysis  of  animal  substances          ....  272 

detection  of  poisons              .....  333 

TAURINE            ........  240 

Tobacco,  detection  of    -  .  .  .  .  .  .330 

Torula     .........  77 

Triple-phosphate  calculi            ......  154 

deposits          .                                                                .  45,70 

Trommer's  test  for  sugar           .             .             .                          .            .  73 

Troy  weight        ........  341 

Tyrosine  in  urine            .......  122 

i 

URATE  of  ammonia        .......  32 

calculi          .             .             .             .             .             .  153 

deposits 

lime  in  calculi          ......  158 

lithia             .......  32 

potash        .  . 

soda              .            .            .            .            .            .            .  32,  66 

in  the  blood                 .....  219 

Urea       ........  27 

detected  in  organic  mixtures         .                                       .  267 

excess  of,  in  urine              ......  64 

in  the  blood            .......  217 

method  of  estimating         .  .  .  .  •  .48 

Davy's         .....  102 

Leconte's     .....  100 

Liebig's       .....  96 

nitrate  of    ........  30 

oxalate  of  .  .  .  .  .  .  .  .29 

Uric  acid            ........  31 

calculi  of        .......  151 

deposits            .......  103 

detected  in  organic  mixtures                                                    •  271 

excess  of,  in  urine       ......  65 

in  the  blood    .......  219 

Uric  oxide           ........  152 

Urinachyli         ........  25 

potus        ........  25 

sanguinis              ......  25 

Urinary  calculi  .....  .150 

deposits,  examination  of          ...                         •  124 

microscopic  examination  of 

Urine,  albuminous,  quantitative  analysis  of    .                                       .  146 

chylous   ......  87 

•  coloring  matter  of          ...... 

containing  albumen        ......  79 

alkapton        ......  79 

bile    .......  83 

blood              ......  82 

cystine          ......  121 

fat      .  .  .  .  .  .  .87 

iodine,  &c.     .  .  .  .  .  .93 


INDEX.  351 

PAHR 

Urine  containing  oxalate  of  lime          .  ...          89 

pus     . 

semen  ......          88 

urate  of  soda  .....  66 

determination  of  acidity  of        .....  60 

diabetic  .......          71 

quantitative  analysis  of  .  .  .  .         137 

healthy  .  ....          25 

average  composition  of  61 

quantitative  analysis  of  .  .  .48 

specific  gravity  of  .....  26,  123 

morbid    ........          63 

qualitative  examination  of  .  .  .94 

with  excess  of  alkaline  salts      ....  69,  111 

earthy  phosphates  .  .  .  69,  111 

extractive  matters         ...  68,  109 

hippuric  acid      ....  67,  107 

mucus  ....  67,  108 

urate  of  ammonia          ...  65,  104 

urea        .....  64,  95 

uric  acid  ....  64,  103 

Urinometer        .....  123 

Uroglaucine       ........  41 

Urohacmatin       ........          40 

Urostealith         ........         161 

Uroxanthin        .  .  ...          41 

Urrhodin  ........          41 

VENOUS  blood,  composition  of  .....        209 

Vesical  mucus    ........          38 

WATER,  detection  of  lead  in     .  .  .  .  .  .        299 

Weights  and  measures  ......        341 

XANTHIC  oxide  .......        152 

ZINC,  detection  of,  in  organic  mixtures  .  .  .  .307 


AN  INITIAL  FINE  OP  25  CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
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